On Tuesday, I wrote about how difficult it is to measure the culture of constant fear that women live with in a world where we're taught to be leery of unknown men and intimate partners alike.

This fear of violence is as profound as violence itself because it shapes -- and narrows -- the lives of women in so many small ways: We forgo a nighttime event because we don't want to travel home alone afterward. We forgo an evening jog because running at night is a luxury only men possess. We forgo a comment or an outfit or a friendship because it might imply an invitation we don't wish to convey.

All of these factors are impossible to capture in typical statistics on violence against women. But Scott Clement, a polling analyst at The Washington Post, found one data set for me that begins to speak to this more unseen (and often unmeasured) side of how women see the world as a result of perceived threats against them.

Between 1973 and 2012, the General Social Survey  has asked this question of people surveyed in their home: “Is there any area right around here – that is, within a mile – where you would be afraid to walk alone at night?”

These are the responses over time, separately for the share of men and women who have answered "yes":

As of 2012, women were more than twice as likely as men to say they were afraid to walk in their neighborhoods at night alone. Their perceived sense of danger has notably declined since the 1970s, while male fear has remained fairly constant. The shift for women, Clement notes, doesn't appear to be generational. Rates of fear are similar now for women over age 65 as those ages 18 to 39. The same was true in the 1970s.

It's worth noting that crime has broadly declined in the United States since the early 1990s. But it's hard to say how much of women's perception of their safety is attributable to actual declines in crime, and how much is attributable to other factors (like changing social norms about whether it's okay for women to walk around alone).

Part of our lack of data on the consequences of a culture of violence against women stems from the fact that we don't ask enough questions like this one. So let's have some more.