What happened in 1991? Crime has been declining since then, even though the population still increases.
Fall of the Soviet Union
In December of 1991, as the world watched in amazement, the Soviet Union disintegrated into fifteen separate countries. Its collapse was hailed by the west as a victory for freedom, a triumph of democracy over totalitarianism, and evidence of the superiority of capitalism over socialism. The United States rejoiced as its formidable enemy was brought to its knees, thereby ending the Cold War which had hovered over these two superpowers since the end of World War II. Indeed, the breakup of the Soviet Union transformed the entire world political situation, leading to a complete reformulation of political, economic and military alliances all over the globe .http://www.coldwar.org/articles/90s/fall_of_the_soviet_union.asp
My generation was led to believe the Cold War would end in a nuclear holacaust. Instead, the U.S.S.R. collapsed and a huge peace dividend began. The beginning of world wide technology in the form of personal computers led to a period of economic growth that bettered prospects for practically everybody willing to work. Microsoft shipped Windows 3.0 in 1990:)