A new City Council proposal seeks to diversify the Fire Department, “ensuring that the racial, ethnic and gender demographics of the department’s firefighters reflect that of the city’s population as a whole.”

The proposed law is aimed specifically at increasing the number of women in the FDNY; accompanying legislation mandates the upgrading of all firehouses to “establish full integration of a mixed-gender workforce,” with separate bathrooms and sleeping areas.

But it is worth remembering that recruiting, hiring and retention practices in the FDNY are already under the scrutiny of an anti-bias federal monitor. In 2011, the FDNY lost a lawsuit filed by black firefighters who said the department’s multiple-choice tests were racially biased, on the grounds that black applicants disproportionately failed them.

A monitor was assigned to watch over the department, more or less controlling hiring.

In 2014, Mayor de Blasio agreed to a $98 million settlement with the supposed victims of the FDNY’s racism, including “compensatory relief” in the form of back pay and benefits for the people who flunked the supposedly racist test. The department agreed to implement major changes in how it recruits applicants and created a chief diversity-and-inclusion officer to support these efforts.

The 2014 settlement concerned African-American applicants, but the FDNY has assumed broader responsibility to recruit across the demographic spectrum. And while it is true that there aren’t very many female firefighters — roughly 1 percent of the department’s nearly 9,000 Bravest are women — the numbers are growing.

In 2012, fewer than 6 percent of applicants were women; the next time the test was offered, in 2017, that rate had more than doubled, to 12.6 percent.

That’s still not a very high number, especially considering the department’s focus on female recruitment: The FDNY set “diversity and inclusion” as its No. 3 goal in its 2015-17 Strategic Plan, ahead of “improving Service delivery.”

And of the nearly 4,000 women who made the cutoff on the multiple-choice exam, only 3.4 percent scored high enough to get invited to take the physical exam, compared to 6.3 percent of men who passed the cutoff.

Part of the problem could be deep sexism baked into the exam questions, or macho scorn from FDNY recruiters at high-school job fairs, but there may also be a limit to the number of women who care to become firefighters.

The assumption of City Council members Adrienne Adams and Alicka Ampry-Samuel — the lead sponsors of the legislation — that the composition of the Fire Department should “reflect that of the city’s population as a whole” seems at odds with statistical reality and common sense.

Consider the demographics of New York City employment generally — and the kind of jobs that attract women, compared to men. Of 400,000 city employees, for example, 59 percent are women. That’s already skewed from the city’s total employment figures, where women comprise less than half of the workforce.

And there is tremendous variety in employment patterns among and within city departments. There are more than 90,000 teachers in the school system, 77 percent of whom are women. Teachers earn a median salary around $86,000, slightly higher than that of firefighters and police officers.

Women comprise more than three-quarters of city-employed health professionals, social workers and clerical supervisors; almost 70 percent of the city’s 2,800 social scientists; and 60 percent of its 2,700 lawyers.

At the same time, out of 6,300 sanitation workers, only a tiny number, and only 5 percent of our 1,700 municipal “laborers,” are women. Why don’t we hear more noise from the council about getting girls excited about hauling trash, which pays a respectable $75,000 median salary?

Are girls being kept out of the Department of Sanitation by sexism, or is there a legitimate, independent lack of interest on their part in becoming part of New York’s Strongest?

The idea that true equality means there will be no differences in how people choose to arrange their lives is a leftist absurdity. The Scandinavian “gender-equality paradox” shows that countries said to have greater gender equality also have, counterintuitively, less gender balance in science, technology and math fields.

Any parent who has tried to raise kids with gender-neutral toys will confess their ready failure to force boys and girls to play along politically correct lines.

Women who want to become firefighters should be encouraged to do so. But the idea that we mustn’t rest until more than half the FDNY is female is ridiculous.

Seth Barron is associate editor of City Journal.