Defensive Gun Use Map

The Cato Institute has a map that plots defensive gun uses in this country (the ones that are reported alteast). Its based off of news reports, but I wonder how often it is updated... I hear of instances a lot on the evening news where I live, but they are not on the map. Also, I wonder how it takes into account the cases where it may not be deemed a "legal defensive gun use" until after an official investigation is finished (which can take a very long time).