That isn’t what they are saying. I am not sure I believe the statistic but all they are saying is the rate id 67% higher, not total number.
eg (made up stats)
3 out of 1,000 non-bikers are criminals
5 out of 1,000 bikers are criminals
5 is 67% higher than 3
Dude...we’re ALL criminals. Sorry you had to find out this way.