While they are rare, their average frequency over long periods is predictable.
His latest forecast, made last week, called for an average frequency of hurricanes this year.
This is the average frequency of those notes.
At the study start, the average frequency of hot flashes was nearly 10 per day.
These buses run on an average frequency of 50 seconds during peak hours.
Over the course of a day, the average frequency is maintained at the nominal value within a few hundred parts per million.
In the United States, the average frequency of sexual intercourse for married couples is 2 to 3 times a week.
Trains run at an average frequency of three minutes during peak days.
In areas with loud low-frequency noise, the calls had a higher average frequency.
The average frequency and duration of these low wind events was once every 6.38 days for a period of 4.93 hours.