From livescience.com (please note that as this is a post I am sharing from elsewhere rather than one of my own comments are closed)

By sifting through minuscule remnants of ancient solar-system crashes, called micrometeorites, researchers found that the most common types of meteorites today used to be quite rare — and the rarest ones used to be common.

Source: Early Meteorite Bits Reveal Clues About Solar System’s Evolution