re: Based on where we're at in the 11 year solar cycle, I bet I could....
"The average duration of the sunspot cycle is 11.1 years, but cycles as short as 9 years and as long as 14 years have been observed. Significant variations in amplitude also occur. Solar maximum and solar minimum refer respectively to epochs of maximum and minimum sunspot counts. Individual sunspot cycles are partitioned from one minimum to the next."
http://en.wikipedia.org/wiki/Solar_cycle