-79.88% is the change from 507 to 102
Calculation steps:
[( 102 - 507 ) ÷ 507] x 100 = -79.88%
Formula
Percentage change = [(102 - 507) / 507] x 100
Subtract the new number by the original number
102 - 507 = -405
-405 ÷ 507 = -0.7988165680473372
-0.7988165680473372 x 100 = -79.88%