Only 230 out of every 1,000 sexual assaults are reported to police. That means about 3 out of 4 go unreported.

https://www.nsvrc.org/statistics

Many people are afraid to report acts of sexual violence to the police, which they most definitely should not be. A lot of people are afraid of what their partner might do to them. However, people should overcome their fear and simply report it to the police so justice can be served.