6500% is the change from 1 to 66
Calculation steps:
[( 66 - 1 ) ÷ 1] x 100 = 6500%
Formula
Percentage change = [(66 - 1) / 1] x 100
Subtract the new number by the original number
66 - 1 = 65
65 ÷ 1 = 65
65 x 100 = 6500%
Example