A smaller percentage of New York City voters turned out in the November 2021 general election than in any other mayoral election in nearly seven decades. That’s based on final election results certified by the New York City Board of Elections on Tuesday compared with annual turnout figures reported by the agency dating back to 1953.

Just 23% of eligible active voters cast a ballot for mayor — or 1.15 million of 4.95 active voters — down three percentage points from the past two mayoral elections in 2017 and 2013. The voter turnout percentage dips even lower, to 21%, when including both active and so-called inactive registered voters. Those are voters who are registered but must cast an affidavit ballot because the Board of Elections has a question about their residence.

The turnout rates by borough varied. In the Bronx, just 17% of active voters cast a ballot in the mayoral contest, compared with 22% in Brooklyn, 23% in Queens, 27% in Manhattan, and 34% in Staten Island.

Citywide, Mayor-elect Eric Adams secured 66% of the total vote — or 753,801 votes of the 1.15 total. Curtis Sliwa amassed 310,385 votes on the Republican and Independence party lines, or 27%.

While Adams, the outgoing Brooklyn Borough President, won a decisive victory over Sliwa, his voters represent just 15% of the city’s active voters. He performed the best among voters in Manhattan where he captured 78% of the vote, or 219,045 of the 279,217 votes cast; Sliwa only won 13% or 36,668 votes there.

The largest share of the vote went to Sliwa in the Republican stronghold of Staten Island, where he won 65%, or 69,924 votes, compared to Adams’ 28%.

Experts attribute the decline in voter participation to both political and structural factors.

“The lack of competitiveness and the related lack of campaigning is enough to explain the turnout,” said Margaret Groarke, a professor of political science at Manhattan College, pointing to how many races seemed to already be decided after the Democratic primary in June.

Given the vast majority of general election contests were not competitive, “people aren’t mobilizing voters a whole lot, and voters don’t have a sense the vote matters as much,” she added.

“Odd year elections are generally-speaking very voter-suppressive,” said Perry Grossman, supervising attorney for the Voting Rights Project for the New York Civil Liberties Union. “We’re also seeing a significant political hangover from a very high participation 2020 election cycle and at least for an odd year election, in the primary,” Grossman added.

In 2020, more than 3 million New York City voters cast their ballots in the presidential contest. That was 55% of all registered voters, or 62% of active registered voters.

Last year, during the first general election with COVID-19, absentee ballots made up nearly a quarter of the ballots cast. The percentage of absentee ballots cast this past November dropped dramatically, accounting for just 7%, or 85,175 of the total votes in the mayoral election.

During the pandemic, voters have had the ability to cast an absentee ballot citing the potential risk of COVID, but that measure is set to expire at the end of this year. Lawmakers had expected a ballot referendum that would allow for no-excuse absentee ballots to pass in November, but it did not.

Given the ongoing risk posed by COVID, lawmakers are planning to introduce legislation that would allow voters to continue to apply for absentee ballots in the upcoming midterm primary and general elections next year.