It might be every 10 years.
Every 4 years.
every 4 years
Leap years occur every 4 years.
About every 2 years.
Every four years.
30
each census is taken every 10 years
every 2 years
The Census is taken every 10 years.
Many sources agree that pet scans are effective in finding cancer. These scans are said to help determine the location of tumors and whether or not they have spread.
Every three years
100 every 2 years.