Aimee Custis sent along a great map from Trulia, showing the ratio of single (straight) men to single (straight) women across the region:

The Washington metropolitan area and “Bethesda-Rockville-Frederick,” which the Trulia data breaks out separately, have the nation’s highest ratio of women to men among the nation’s 100 largest metropolitan areas.

The zip code with the most male-heavy singles is Rosslyn; the most female-heavy, upper Connecticut Avenue.

Trulia economist Jed Kolko writes:

Billy Joel was right: in most metros, the neighborhood with the highest ratio of men to women is in or near downtown, as well as in recently redeveloped neighborhoods. … The neighborhoods with the highest ratio of women to men tend to be more residential, like San Francisco’s Marina and Seattle’s Queen Anne, and more upscale (and safe), like the Upper East Side and Upper Connecticut Avenue.

What do you notice in the map?