Of those who do report, the FBI's Uniform Crime Reporting database
shows that only about 20% of reports lead to arrest.
According to the nonprofit Rape, Abuse and Incest National Network, which analyzes national data regarding sexual assault and rape, only about half of arrests lead to trial.
The most reliable
data on conviction rates comes from a Justice Department study that analyzed convictions between 1990 and 2009. That study concluded that rape trials end in conviction around 35% of the time.
Taken together, this means that only about 0.8% of assaults lead to a conviction.