AUGUSTA – Voters eager to have their say on the Indian casino and other referendum issues shattered Maine’s turnout record for an off-year election, according to the latest unofficial figures available Wednesday.

Tallies from all 649 of Maine’s precincts show more than 509,000 votes were cast Tuesday in the casino referendum, by many estimates the most provocative item on the six-question state ballot.

That accounts for about 50 percent of Maine’s voter age population, which the state pegs at just over 1 million.

“We’re thrilled, not just for ourselves, but for the state,” said Secretary of State Dan Gwadosky, Maine’s top election official.

Gwadosky said everything was in place for a big turnout, including a high absentee ballot count and having an emotional issue before voters.

“If there’s an emotional issue out there, Maine people tend to show up,” said Gwadosky.

The 50 percent turnout, which could increase as more complete figures come in, is well above Maine’s 44.5 percent record for an off-year election, according to election officials. The record was set in 1987 when a question about whether to close the Maine Yankee atomic plant was on the ballot. Voters decided to keep the plant, which has since been decommissioned, operating.

University of Southern Maine political science professor Richard Maiman acknowledged that the 50 percent figure is high for an off-year election, but said it is nothing to throw a party over.

“I remain unimpressed with the 50 percent figure,” said Maiman. “The glass is still only half-full, and low compared to a presidential election.”

Maine’s modern turnout record, 73 percent, was set in the 1992 election in which Bill Clinton was elected to his first presidential term. Maine also posted the nation’s best turnout figures in the 1996 presidential election, and missed the top spot by less than 2 percentage points in 2000.