The number of views depends on two factors:
1. How often this keyword was search?
2. What page was it on each time?

Views = monthly searches / keyword visibility coefficient

The following figures for the keyword visibility coefficient are applied:
1 = ranked 1-3 (1st page)
0.7 = ranked 4-5 (1st page)
0.5 = ranked 6-10 (1st page)
0.1 = ranked 11-20 (page 2)
0.03 = ranked 21-100 (past page 2)