The above figure is for the cratering rate of the Moon. The cratering rate for the land masses on the Earth is roughly 10 times higher (can you think of reasons why?).
Event Billions of Years Ago Lunar Formation 4.6 surface soft rate is unknown because of cratering saturation--craters overlap destroying evidence of earlier impacts Crust Formation 4.4 Heavily cratered highlands regions are formed Start of Heavy Bombardment 3.9 Basin Formation final heavy bombardment (final surge due to an unique event--debris from disruption of an asteroid?) Maria Formation (filling in of basins with lava flows 3.9-3.2 Slow constant bombardment 3.8 Today 0