The three prequel films were also released at three-year intervals, with the final film of the trilogy released on May 19, 2005.

From then on they are continually involved in motherhood, producing babies at two to three-year intervals.

The three-year interval may not be correct.

Five more such festivals using more modest forces followed at three-year intervals.

Assume that they left Mars at some time during the three-year interval following their departure from Heraldic.

Mass treatment has been recommended at six-month to three-year intervals, depending whether there is a continuous high or seasonal low transmission (more often with the former).

In 1980 the cancer society changed its recommendation to a three-year interval.

Detroit was content to make trivial product design changes at three-year intervals, but the electronics industry routinely expected order of magnitude advances in the same time.

As you see, the earliest records are in three-year intervals.

Subsequently, conferences have been held at two- or three-year intervals with published preprints on a topic of current interest.