The slate of Democratic candidates for the 2020 presidential election, vast and growing, includes many current and former members of Congress.

Their records in the Senate and the House of Representatives may give some indication of how they would perform as president. (The legislative seats are full-time jobs that pay an annual salary of $174,000 and generally require elected members to be in Washington, DC for about one-third of the year.)

Quartz charted data from GovTrack—a site that tracks legislation and voting records and writes a “report card” for each candidate—to get a sense of how productive and involved they had been in Congress. (GovTrack says it “receives no funding in any form from outside organizations,” and has no political affiliations.)

Total enacted bills, lifetime

This category refers to the number of bills a lawmaker was the primary sponsor for over their entire time in office that have gone through the lengthy (and rare) process of becoming a law.

Among the presidential candidates, Amy Klobuchar, the senator from Minnesota, has been the top sponsor of passed bills, according to GovTrack. Klobuchar has successfully pushed bills on everything from women’s entrepreneurship to water- and wildlife-restoration acts to drug-disposal measures.

Ranking the candidates by enacted legislation isn’t an apples-to-apples comparison—some candidates have been in Congress much longer than others. Kamala Harris first joined Congress as a senator in 2017, for example, while Sanders has been in Congress since 1991 (first as a House member and, since 2008, as a senator).

And some bills require more work than others to get passed. Two of the seven successful bills that Sanders has sponsored since 1991 were to rename post offices, and a third was a declaration of a Vermont “bicentennial day.”

Lifetime “missed votes” record

Sanders has the worst track record among candidates for “missed votes,” at 6.4% of all votes from January 2007 to February 2019, well above the Senate lifetime median of 1.3%. That appears to be due mostly to a jump in missed votes when he was campaigning for the Democratic nomination for president in late 2015 and 2016.

Booker was also above the median, at 3.3% from October 2013 until February 2019. The House lifetime “missed vote” median is 2.0%, which both John Delany, a former Maryland representative and Tulsi Gabbard, a representative from Hawaii, surpassed.

115th Congress co-sponsored bills

This is more of an apple-to-apples comparison than lifetime-enacted bills, in that it looks just at performance in one legislative session, the 115th Congress (which met from Jan. 3, 2017 to Jan. 3, 2019). GovTrack considers co-sponsorship important because it “shows a willingness to work with others to advance policy goals.”

115th Congress enacted bills

This category only counts bills that a member introduced and that became a law during the 115th Congress. Republicans controlled both the House and the Senate during that session, making it more difficult for Democrats to get bills introduced and passed.

The difficulty of getting the bills passed varies depending on subject, so it is worth looking deeper at the actual bills the senators and members of the House passed during the 115th Congress. New York senator Kirsten Gillibrand’s eight bills enacted in the 115th Congress include five post-office renamings, for example, while Massachusetts senator Elizabeth Warren’s five bills include one.

An earlier version of this article incorrectly identified Klobuchar as a senator from Missouri.