What's the Meaning of Wet Years?

archaeologist found that the wettest decades in the last two thousand years in mongolia were the three decades around the birth and the childhood of gengus khan. The anasasi developed an agricultural society in areas of desert where nobody makes a living by agriculture to day. A time capsule tells you what was growing within 20 meters of this nest within 30 years of the year 11 18, which was also the beginning of the anisase abandonment.