San Luis Obispo County voters appeared to turn out in large numbers for this presidential election, but voter turnout was lower than four years ago, according to preliminary estimates from the county.

In 2008, 83 percent of registered voters cast ballots compared to an estimated turnout of roughly 80 percent this year, according to county Clerk-Recorder Julie Rodewald.

With 43 percent of votes counted, 68,440 ballots had been cast as of 10:45 p.m. Tuesday. Forty-three of 147 precincts had reported to the county as of that time.

Most of those votes were mail-in ballots, equaling more than a third — 36.9 percent, or, 58,600 — of the county’s 158,603 registered voters. In 2008, there were 73,038 vote-by-mail ballots.

As of September, the county’s registered voters declined by 1.6 percent from 2008, according to the county.

Registration numbers for the Democratic Party dropped 7 percent, and the Republican Party saw a 4 percent decline in registration. But the number of voters not registered with either party grew by 11 percent.