It's not a lack of data so much as how we interpret what we already know.
We know that young women are far more likely to be targeted. Probably general level of attractiveness has some impact - I imagine hot girls and ugly girls face the most harassment. If we were to break incidents down by number of harassments per number of interactions with a stranger, you'd probably see consistency between rural and urban areas. However, due to higher population density, you'd have a higher frequency in urban areas. We know that the statistics don't suggest any one race is more associated with street harassment - women of all races experience it, and men of all races do it.
So, like I said, this has nothing to do with race. There is no connection to Emmett Till or black culture or history. And I'm not being white privileged by pointing out that blacks aren't predisposed to harassing women due to cultural influences.