ORLANDO, Fla. — The number of Florida Republicans is up by more than 6 percent compared to the last presidential preference primary four years ago, and voter registration numbers released Tuesday show that the biggest gains were in counties where presidential candidate Mitt Romney did well in 2008.

An Associated Press analysis shows that more than 90 percent of the gains in registered Republicans were in Florida counties where Romney finished in either first or second place in the 2008 primary. A third of the GOP registration gains were in counties where Romney actually took first place. Romney came in a strong second-place in the 2008 Florida primary behind eventual-nominee John McCain in a field of nine candidates.

The biggest gains in registered Republicans since 2008 have been in Lee, Broward, Orange, Hillsborough and Escambia counties.

Florida Republicans are set to pick their presidential candidate on Jan. 31, although the GOP race could be decided this weekend if Romney wins the South Carolina primary.

Florida Democrats have outpaced Republicans in registering new voters since the last presidential primary. The number has grown10 percent during the past four years, and Democrats now outnumber Republicans by almost a half-million registered voters.

At the start of January, Florida has 4.5 million Democrats and more than 4 million Republicans.