661.54% is the change from 13 to 99
Calculation steps:
[( 99 - 13 ) ÷ 13] x 100 = 661.54%
Formula
Percentage change = [(99 - 13) / 13] x 100
Subtract the new number by the original number
99 - 13 = 86
86 ÷ 13 = 6.615384615384615
6.615384615384615 x 100 = 661.54%