-67.8% is the change from 500 to 161
Calculation steps:
[( 161 - 500 ) ÷ 500] x 100 = -67.8%
Formula
Percentage change = [(161 - 500) / 500] x 100
Subtract the new number by the original number
161 - 500 = -339
-339 ÷ 500 = -0.678
-0.678 x 100 = -67.8%