Here is a list of all 51 governments that appoint electors in order by population (according to the 2010 census) and the number of electors each may appoint for the 2012, 2016 and 2020 elections (the numbers in parentheses are the changes, if any, from 2008):
California... 55
Texas... 38 (+4)
New York... 29 (-2)
Florida... 29 (+2)
Illinois... 20 (-1)
Pennsylvania... 20 (-1)
Ohio... 18 (-2)
Michigan... 16 (-1)
Georgia... 16 (+1)
North Carolina... 15
New Jersey... 14 (-1)
Virginia... 13
Washington (state)... 12 (+1)
Massachusetts... 11 (-1)
Indiana... 11
Arizona... 11 (+1)
Tennessee... 11
Missouri... 10 (-1)
Maryland... 10
Wisconsin... 10
Minnesota... 10
Colorado... 9
Alabama... 9
South Carolina... 9 (+1)
Louisiana... 8 (-1)
Kentucky... 8
Oregon... 7
Oklahoma... 7
Connecticut... 7
Iowa... 6 (-1)
Mississippi... 6
Arkansas... 6
Kansas... 6
Utah... 6 (+1)
Nevada... 6 (+1)
New Mexico... 5
West Virginia... 5
Nebraska... 5
Idaho... 4
Hawaii... 4
Maine... 4
New Hampshire... 4
Rhode Island... 4
Montana... 3
Delaware... 3
South Dakota... 3
Alaska... 3
North Dakota... 3
Vermont... 3
District of Columbia... 3
Wyoming... 3
1) California - 55
2) Texas - 34
3) New York - 31
4) Florida - 27
5) Ilinois - 21
6) Pennsylvania - 21
7) Ohio - 20
8) Michigan - 17
9) Georgia - 15
10) New Jersey - 15 11) North Carolina also has 15
All ten of Minnesota's electoral votes go to the Presidential candidate with the most popular votes in the state and his running mate.
Ten.
Each of the States of Maryland, Minnesota, Missouri and Wisconsin will appoint ten electors in each of the Elections of 2012, 2016 and 2020.
Assuming you refer to the United States, that would be the national census.
Although the number of Electoral Votes a state may have can fluctuate, Arizona received 10 electoral votes in the last presidential election. These votes went in support of Republican Sen. John McCain.
All ten were for Obama.
Mitt Romney was unable to win Wisconsin in the 2012 election; the state awarded its ten electoral votes to President Obama.
Mr. Romney did not win the state of Minnesota in 2012; the state's ten electoral votes went to President Obama.
Each state has as many votes as it has Congressional representatives and Senators combined. The total number of electoral votes is 435 (3 for District of Columbia). Every state has two senators and so has at least three electoral votes.
In the United States, the number of electoral votes each state gets in a federal election depends on their population, which is calculated after the census is taken every ten years.
1988: George H. W. Bush wins 29 electoral votes from Texas.1992: George H. W. Bush wins 32 electoral votes from Texas.2000: George W. Bush wins 32 electoral votes from Texas.2004: George W. Bush wins 34 electoral votes from Texas.
One could win the US presidential election without the ten states with the highest number of electoral votes (256), although since numbers nine through eleven each have 15 votes if all eleven of the states with the most electoral votes went for one candidate there is no way the other candidate could win (271 votes against). In the 'top ten ' scenario, all of the remaining states, with the exception of Massachusetts (12 votes) would have to be won by the candidate collecting electoral votes from the smaller (when calculated by electoral votes) states.