-61% is the change from 100 to 39
Calculation steps:
[( 39 - 100 ) ÷ 100] x 100 = -61%
Formula
Percentage change = [(39 - 100) / 100] x 100
Subtract the new number by the original number
39 - 100 = -61
-61 ÷ 100 = -0.61
-0.61 x 100 = -61%
Example