Each subject area is tested at 4-5 year intervals, rather than annually.

Table 3.6 shows each major ownership group's share of titles and circulation at 10 year intervals.

Since then, there have been general elections of the council at four year intervals.

This may make it necessary to burn at five to ten year intervals in order to reduce its populations.

High production cows are more difficult to breed at a one year interval.

The exhibition has been held every two years, except for a three year interval between 2005 and 2008.

F17 and F19 will follow at 3 year intervals, or as needed.

Each successive mission (if funded) would be at two year intervals.

It was neat to keep this even two thousand year interval.

I seem to visit Spain at four year intervals.