-83.98% is the change from 618 to 99
Calculation steps:
[( 99 - 618 ) ÷ 618] x 100 = -83.98%
Formula
Percentage change = [(99 - 618) / 618] x 100
Subtract the new number by the original number
99 - 618 = -519
-519 ÷ 618 = -0.8398058252427184
-0.8398058252427184 x 100 = -83.98%