-51.18% is the change from 170 to 83
Calculation steps:
[( 83 - 170 ) ÷ 170] x 100 = -51.18%
Formula
Percentage change = [(83 - 170) / 170] x 100
Subtract the new number by the original number
83 - 170 = -87
-87 ÷ 170 = -0.5117647058823529
-0.5117647058823529 x 100 = -51.18%