Currently, the ratio of legal to illegal activity on the bitcoin network has completely changed trend as the former surpasses the former. This was stated by DEA Agent Lilita Infante at the U.S Drug Enforcement Administration.
Is the number of criminals on the bitcoin network has significantly reduced compared to early days?
the dates mentioned here are quite wrong.
the early days there were no criminal activity. then in a couple of years it increased with things such as SilkRoad and the dark market and the fact that people thought bitcoin is anonymous. but even then at the peak there wasn't more illegal activity than legal activity ever. then as SilkRoad was closed and as people found out bitcoin has never been anonymous the illegal activities dropped down significantly. this is years ago!