Extinction sized impacts on the Earth occur about every 100 million years.

Seed production occurs after about four years of age.

This period occurred about 380,000 years after the Big Bang.

In general, the time of diagnosis usually occurs from about 2 to 4 years of age.

Some readings of the fossil record show that mass extinctions seem to occur about every 26 million years.

It may only occur about every five to ten years.

This is thought to have occurred about 377,000 years after the Big Bang.

The closest approach to the Sun will occur in about 88,600 years when this system will come within 1.95 parsecs.

According to one detailed study, macular degeneration generally starts to occur in people at about 50 years of age.

Sexual maturation for these animals occurs at about two years of age.