-64.12% is the change from 170 to 61
Calculation steps:
[( 61 - 170 ) ÷ 170] x 100 = -64.12%
Formula
Percentage change = [(61 - 170) / 170] x 100
Subtract the new number by the original number
61 - 170 = -109
-109 ÷ 170 = -0.6411764705882353
-0.6411764705882353 x 100 = -64.12%