This is from the FBI Uniform Crime Statistics. You can see that there is a fairly low rate of violence in the '50s and the '60s, then it soared upward for several decades, and began a precipitous decline, starting in the 1990s, so that it went back to the level that was last enjoyed in 1960.
See on FBI Kuritegude statistika: te näete, et 50ndatel ja 60ndatel oli vägivalla tase madal, siis see tõusis paari aastakümne vältel ja hakkas alates 1990ndatest järsult langema, jõudes tagasi samale tasemele, mida viimati nauditi 1960ndatel.