-51.2% is the change from 209 to 102
Calculation steps:
[( 102 - 209 ) ÷ 209] x 100 = -51.2%
Formula
Percentage change = [(102 - 209) / 209] x 100
Subtract the new number by the original number
102 - 209 = -107
-107 ÷ 209 = -0.5119617224880383
-0.5119617224880383 x 100 = -51.2%