USGS: Earthquake Facts and Statistics
Frequency of Occurrence of Earthquakes Magnitude Annually 8+ 1 * 7 - 7.9 17 * 6 - 6.9 134 * 5 - 5.9 1,319 * 4 - 4.9 13,000 (estimated) 3 - 3.9 130,000 (estimated) 2 - 2.9 1,300,000 (estimated) * Based on observations since 1900.
Magnitude Annually 8+ 1 * 7 - 7.9 17 * 6 - 6.9 134 * 5 - 5.9 1,319 * 4 - 4.9 13,000 (estimated) 3 - 3.9 130,000 (estimated) 2 - 2.9 1,300,000 (estimated) * Based on observations since 1900.