Poor and middle-income Americans are reaching deeper into their pockets when donating to charity, while the nation’s wealthiest are giving less, according to a report by Chronicle of Philanthropy that analyzed taxpayers’ IRS data.

On average, Americans give about 3 percent of their income to charity each year, according to the report released Monday. But the giving gap between the rich and poor is significant, especially in view of the widening income gap. The report shows those who earned $200,000 or more donated 4.6 percent less of their income between 2006 and 2012; those who earned less than $100,000 gave 4.5 percent more.

Why? Chronicle editor Stacy Palmer noted one factor: church attendance.

Utah residents proved to be the most generous, with a giving rate of 6.6 percent — for every $1,000 they brought in, they handed out $65.60. Utah is also known for its large population of Mormons, whose church asks them to give at least 10 percent of their income to charity. New Hampshire residents were the least giving, with a rate of 1.7 percent. Maine and Vermont weren’t so charitable either, also ranking among the lowest.

Palmer suggested the meager handouts in northern New England are partly because of low rates of church attendance, but the low rankings also stem from residents’ “independent streak” and a tradition of self-reliance.

However, America’s wealthy are more inclined to support the arts and higher education than poorer donors, the report said.

The report analyzed tax returns filed by tax-payers who itemize their deductions, including charitable gifts.

Here are the top 10 most generous states:

1. Utah: 6.6 percent giving rate
2. Mississippi: 5.0 percent
3. Alabama: 4.8 percent
4. Tennessee: 4.5 percent
5. Georgia: 4.2 percent
6. South Carolina: 4.1 percent
7. Idaho: 4.0 percent
8. Oklahoma: 3.9 percent
9. Arkansas: 3.9 percent
10. North Carolina: 3.6 percent

Of the 50 largest cities, Las Vegas saw the biggest jump in generosity. Residents gave nearly 15 percent more of their incomes to nonprofits between 2006 and 2012. And Nevada was the state with the fastest-growing donation rate.

Buffalo-Niagara Falls, N.Y., was the city that took the deepest dive — 10.6 percent. And North Dakota was the state that saw the biggest decline in donations, despite its sudden riches from the boom in fracking.

Here are the top 10 most generous cities:

1. Salt Lake City: 5.4 percent in 2012, up 2.7 percent from 2006
2. Memphis: 5.1 percent, up 6.7 percent
3. Birmingham, Ala.: 4.8 percent, up 1.7 percent
4. Atlanta: 4.0 percent, up 6.5 percent
5. Nashville: 3.9 percent, up 4.8 percent
6. Jacksonville, Fla.: 3.8 percent, up 8.7 percent
7. Oklahoma City: 3.7 percent, down 1.6 percent
8. Dallas-Fort Worth: 3.6 percent, up 4.6 percent
9. Charlotte, N.C.: 3.4 percent, down 5.5 percent
10. Virginia Beach: 3.3 percent, down 6.1 percent