Finding a percentage in a grid/polygon

Discussion created by bgmartai on Sep 13, 2013
Latest reply on Sep 19, 2013 by bgmartai
Hello everyone,

I'm working on a state level map and I have a year's worth of crashes. The crash data includes age.
Younger drivers, by the standards I'm looking at, are between the ages of 16 and 19, inclusive. I have 1 square mile grids over the state (used Fishnet tool), and need to find the percentage of younger drivers out of all drivers in each grid.
That is to say, if a grid has 100 drivers total, and 20 of them are younger, then it would equal 20% or 0.2. The point of this is to have these percentages get color-coded and look at where younger drivers cause more crashes than in other locations.

I have no idea how to go about this, as I do not know how to VB Script (I looked at the Field Calculator in the Attribute Table, but wasn't sure what to do with it).

I'm using Desktop 10.0, SP 5.