-31.6% is the change from 500 to 342
Calculation steps:
[( 342 - 500 ) ÷ 500] x 100 = -31.6%
Formula
Percentage change = [(342 - 500) / 500] x 100
Subtract the new number by the original number
342 - 500 = -158
-158 ÷ 500 = -0.316
-0.316 x 100 = -31.6%