The sitting of a congress is for a two-year term, at present beginning every other January; the current congress is the 117th. Elections are held every even-numbered year on Election Day. The members of the House of Representatives are elected for the two-year term of a congress. The Reapportionment Act of 1929 establishes that they be elected in single-member constituencies or "districts" by first-past-the-post and that congressional districts be apportioned to states by population every ten years using the United States Census results, provided that each state has at least one congressional representative. Each senator is elected at-large in their state for a six-year term, with terms staggered, so every two years approximately one-third of the Senate is up for election. Each state, regardless of population or size, has two senators, so currently, there are 100 senators for the 50 states.