This post has been corrected.

Between April 2013 and March 2014, the offices of U.S. senators from California, Texas, Florida and New York led the the country in spending, according to data digitized by the Sunlight Foundation.

During that time period, Senate offices claimed about $2.5 million on average; combined, the offices spent $267 million. Almost all of that cost -- over $253 million -- was in the form of staff salaries. Another $9 million was spent on transportation for senators and their staffers; $2 million more was incurred from per diems.

An important note: This doesn't include costs for the leadership offices, such as those of Sens. Harry Reid (D-Nev.) and Mitch McConnell (R-Ky.) -- just their Senate offices.

As noted above, the senators from some of the largest states reported the most spending to the secretary of the Senate, according to the biannual reports that the Sunlight Foundation put into easy-to-read format. (Bless them!) We took the Sunlight data and flagged salary spending, transportation spending and per diems by either the senator or senate staffers. (The transportation segment was inspired by one of the first uses of the data: USA Today's report last week on charter flights used by senators.)

Here's a sorted list of how the senators compare on total spending.

And here's how they compare in each category. We'll break some of it out below.

According to our analysis, California Democratic Sens. Barbara Boxer and Dianne Feinstein had the most expensive offices. Close behind, though, were three Republicans, including two that have set their sights on 2016: Sens. Ted Cruz (Texas) and Marco Rubio (Fla.). New senators spent less, with the exception of Cruz, for perhaps obvious reasons. But so did senators from less populous states and states closer to Washington -- i.e. less on transportation and fewer field offices.

The amount spent on transportation and per diems per senator, though, is interesting. Sen. Chuck Schumer (D-N.Y.) spent far more than his colleagues on transportation, according to the data. In second? Sen. John Barrasso (R-Wyo.).

Sen. Jerry Moran (R-Kan.) and Sen. Mike Enzi (R-Wy.) lead the pack on per diems collected, augmenting their $174,000 salaries with another $8,000-plus in per diems each. A number of senators didn't collect any per diem at all.

There's a wealth of other data in the Sunlight Foundation set. Curious how much the Senate's three elevator operators make? Sunlight has the data.

One last bit of data, as spotted by The Washington Post's Chris Ingraham: The Senate spent over $370,000 in staff costs on hair stylists and barbers during that time period -- and a paltry $7,700 for a shoe-shine attendant.

Update: Alex Conant, press secretary to Sen. Rubio, offers a response.

It's not news that Senate budgets are determined by state populations, with senators representing more populous states like California, Florida and Texas having larger budgets for constituent services, state offices and travel. Since his election, Senator Rubio has made constituent services a top priority -- in fact, we recently held our 500th mobile office event, helping Floridians with everything from veterans benefits to expediting passports. Florida is a big state with a very diverse population, but for the last four years we've been able to help constituents in need while also returning part of our budget to the US Treasury every year.

Correction: A error in our data analysis incorrectly attributed one transportation expense of Sen. Cruz to his per diem spending, causing us to incorrectly state that his per diem costs were the highest. As the chart now indicates, they are not.