The shooting of an unarmed teenager in Missouri this month led to increased scrutiny of the composition of police departments. Closer to home, the death of Eric Garner at the hands of the NYPD has sparked widespread outrage and a renewed effort to reform the department.

Over at FiveThirtyEight, Nate Silver broke down the numbers and found that most police officers in America don't live in the city they serve, often opting for suburbs outside of the communities they police. While the civil unrest in Ferguson has drawn attention to the huge racial disparity between the police and the policed, Silver points out that New York City actually has a majority of NYPD officers living within city limits. But that's where a telling divide can be seen—almost 80% of black police and 76% of hispanic officers live in the city, while only 45% of white police officers live within city limits. And that includes Staten Island.

For decades, proposals for a residency requirement for NYPD officers have been floated and gone nowhere. The most recent bill to actually come to a vote on the idea was proposed by then-assemblyman Hakeem Jeffries in 2011, after several NYPD officers made racially-motivated remarks on Facebook about the West Indian Day Parade.

"The racial intolerance that has festered in this department has reached an extreme level, and it is necessary that we take steps to remedy the situation," Jeffries said at the time, calling on a new law that would revise the current requirement of having to live in either NYC, Nassau, Westchester, Rockland, Orange, or Putnam Counties.

But the Policeman's Benevolent Association countered that the cost of living in New York City was too high for officers to be expected to live there (even though, once again, at least 75% of all black and hispanic police officers somehow make it work). Many other municipal workers have to deal with residency requirements in order to work for the city, although several loopholes often allow them to live in the suburbs as well.

Right now Philadelphia and Chicago each have high rates of officers living within city limits (Philadelphia has a residency rule with some exceptions, but still keeps most officers in city limits). In Pittsburgh, police officers are fighting against a 1902 law that compels them to live within city limits.

NYPD officers had to live within the five boroughs until 1962, when the regulations were relaxed to include the northern suburbs and Long Island.