For each of the last 17 years a small office on the top floor of the General Services Administration headquarters building has accumulated a roomful of paper and computer tapes detailing the properties owned and leased by federal agencies.

And each year the staff turned the mountains of paper and tape into a series of bulky volumes.

Researchers, statisticians and even Safeway executives trying to find out what leased space was going for around the country found the project a gold-mine.

Federal decision-makers did not.

As a result, GSA officials have decided to change what goes into the chest-high stack of print-outs and the 2,000-to-3,000-page annual report.

Robert L. Auster, director of GSA's public buildings financial management division, said that in fiscal 1984 agencies will be asked to include information that will help GSA manage federal space holdings and real property--part of its new working orders over the last two years from the White House.

"In the new system we'll be asking agencies how many people are located in office space that is being reported," Auster said. "And we'll ask agencies to cite what they regard as the highest and best use of the property. In addition, they'll be asked to assess the current value of the property rather than continue to report acquisition costs."

Much of the information in the report is basic: the feds own 729,820,861.4 acres of land around the world--ranging from a home at 1600 Pennsylvania Ave. NW to a 1,378-square-foot office building on Johnson Atoll in the Pacific Ocean. Holdings also include the Bridge Canyon Project in Arizona--the largest federal reclamation and irrigation project--to a 90.1 acre Central Intelligence Agency "monitoring site" on Riverside Road in Oxon Hill.

Overall, the government owns 387,396 buildings and leases another 6,558. The Postal Service has 50.3 percent of all leases--30,638. The Federal Aviation Administration owns the most properties, 9,094 although most are tiny beacon and antenna sites.

The top land-owning and property-leasing agencies include the Army (with 7,936 properties), GSA (6,148 properties), the Air Force (3,427 properties), the Soil and Conservation Service (2,589 properties), the Army Corps of Engineers (1,956 properites) and the Farmers Home Administration (1,837 properties). There are 27 land-owning and 18 land-leasing agencies. Government property statistics do not include Defense-owned properties abroad, which are withheld, Auster said, for security reasons.

Hidden in the fine-print type are answers to questions that it is unlikely anyone ever thought to ask.

For example, there are six Navy installations in Indiana; the U.S. Mint facility at Fort Knox covers 74.5 acres and has one 30,400 square-foot building; the Bureau of Indian Affairs owns 1,619 acres in Massachusetts.

Among other nuggets in the FY 1982 report:

* Acquisitions: During its history, the U.S. has acquired $10.8 billion worth of land; constructed or acquired $47.6 billion worth of buildings and erected another $59.4 billion worth of other structures, ranging from dams to airfields.

* Leases: There are 60,907 U.S. leases for land or building space at 49,112 locations. The annual rent of $1,056,566,284 for 204,121,459 square feet of building space averages to $5.18 per sq. ft. GSA is responsible for the bulk of the leasing dollars, $650,387,108 for 5,050 locations.

* Rents: New York City has 493 leases, Council Bluffs, Ia., has four. The District, with 171 leases, is tied for third with Chicago. Los Angeles has 184 leases. It cost taxpayers $121,280,832 to rent space in the District. In Arlington, it cost another $46,417,014. New York City ranked third ($44.03 million) followed by San Francisco ($21.35 million) and Los Angeles ($17.25 million). The leases in Council Bluffs cost $49,372 a year. The U.S. has 15.1 million square feet of leased space in D.C.; New York City is a distant second (5.75 million sq. ft.) with Arlington close behind (5.54 million sq. ft.) Oklahoma City is fourth (2.93 million sq. ft.).

* Abroad: The U.S. owns 27,862.3 acres in Panama, the most of any country. It leases 6,581.2 acres in India, again tops. The U.S. owns or leases more than 1,000 acres in Liberia (5,017 acres), the Philippines (1,803 acres) and Senegal (1,603 acres). Overall, the U.S. has 6,852 leases abroad covering 19,529.4 acres and 25,333,433 square feet of building space. The annual rent abroad is $110,794,955 with the largest slice--$4.9 million--going to Mexico. Egypt ranks second ($4.81 million), followed by Nigeria ($3.01 million), France ($2.96 million) and the Philippines ($2.92 million).

* Environmental and historic property: The Interior Department owns 260.88 million acres of forest and wildlife land and 100.36 million acres of parkland and historical properties. Alaska has the most of both. The District is the only jurisdiction without a forest or wildlife property; Delaware is the only state without a federal park or historical area.

* Research and development: The bulk of the 724,314 acres devoted to R&D facilities is controlled by the USDA. New Mexico has the most U.S.-owned R&D land, 236,600 acres. The largest federally-leased R&D facility is a 40,000 sq. ft. Navy Oceanographic Systems Center in San Diego. The most expensive R&D facilities is NASA's Kennedy Space Center in Florida. Acquisition cost: $287.6 million.

* Hospitals: The largest U.S.-leased hospital is a 24,195 sq. ft. VA outreach center leased for $171,000 a year in New Orleans, La. The smallest, covering 780 square feet, is in Memphis, Tenn., and rents for $4,565 a year. The government owns 248 hospitals in California; but only four in Delaware and Rhode Island.

* Prisons: The U.S. owns 140 federal prison buildings in Texas. Leavenworth, in Kansas, covers 500.3 acres and has 67 buildings. The land cost the U.S. $7.7 million to acquire.

* Public works: The U.S. owns $1.7 billion worth of bridges and roads in Oregon. The most money spent to acquire railroads was in Alaska: $98.6 million.

* Farm and ranchland: The U.S. owns 3,111 acres of agricultural land but 161.77 million acres of grazing land. Most of the agricultural land is in Missouri, 912.2 acres; most of the grazing land--53,334,401 acres--is in Nevada.

* Waterways: The Defense Department controls virtually all of the 45,631 acres of U.S.-owned ports and harbors. Most the 8.5 million acres of flood control and navigation projects are run by the U.S. Army Corps of Engineers. Remarkably, Nebraska's 30,247.8 acre Harlan County Lakeside property is considered the largest "harbor or port." Oklahoma has 1.07 million federal acres devoted to flood control and navigation projects.

* Monuments and memorials: More money has been spent erecting government-owned monuments and memorials in Louisiana than in the District. The reason: a $25.4 million Saturn Booster rocket on display at a NASA facility. Acquisition cost of monuments and memorials here has been only $21.6 million in appropriated funds since the 1700s--ranking it third, after Missouri. Apparently, most of the District's monuments are counted as historic structures under another category or were paid for, at least in part, with private funds.