Nebraska, by the way, has had one of the nation's most liberal laws on pot for decade: it is an infraction to possess less than an ounce in the Cornhusker State, carrying a fine of $100. In terms of the penalty, that's far less than a ticket for minor in possession of alcohol, and on par with your average speeding ticket.
I ran the numbers for 2014, year to date (January 1 through April 15). Then I did the same time period in previous years. There are Incident Reports classified as drug cases, that include the word "marijuana." The results seem to bear out my theory.