-69.9% is the change from 515 to 155
Calculation steps:
[( 155 - 515 ) ÷ 515] x 100 = -69.9%
Formula
Percentage change = [(155 - 515) / 515] x 100
Subtract the new number by the original number
155 - 515 = -360
-360 ÷ 515 = -0.6990291262135923
-0.6990291262135923 x 100 = -69.9%