SIOUX FALLS (AP) – The number of speeding tickets issued by South Dakota state troopers has gone up since the state's top speed limit increased from 75 mph to 80 mph nearly two years ago.

According to an analysis of ticket data by the Argus Leader, in the nearly two years before the speed limit increase, troopers wrote 12,585 speeding tickets on interstates and state highways. For the same period following the change, troopers wrote 18,227 citations.

The surge began on day one. During the month of April 2015, a total of 1,012 tickets were issued. That's more than double the 465 tickets issued in April 2014.

The newspaper reported that while the numbers show the Highway Patrol is more aggressive at enforcing the speed limit, they don't show whether troopers are writing more tickets to speeders who were only slightly speeding, or whether they were giving motorists more leeway before the speed limit changed. That's because the Highway Patrol wouldn't release the speeds of motorists cited. Argus Leader Media filed an appeal, which is pending.

In a statement, Department of Public Safety spokesman Tony Mangan said troopers are free to use discretion when they stop motorists, and he credited the increase in tickets to hard-working, self-motivated troopers. He said the Highway Patrol does not have a quota system.

"The Highway Patrol has always provided direction to its troopers on the application of the law as it pertains to speed enforcement in an effort to provide a consistent and equitable policy," he said. "This is to ensure all officers perform their duties in a similar manner. This direction does not take away officer discretion or common sense."

The Argus Leader Media's analysis of ticket data also found that men received 66 percent of the tickets written since 2013. While the majority of tickets were issued to motorists on Interstates 90 and 29, the number of tickets written on back roads and state highways more than doubled since the limit went up.

The data also shows the busiest days for tickets fall around Independence Day, Memorial Day and Labor Day. The busiest day was Friday, July 3, 2015, when troopers wrote 165 tickets.

The National Safety Council reports that highway traffic deaths increased nationwide in 2016. But in South Dakota, fatalities were down to 115 last year, the lowest since 2011.