-31.41% is the change from 503 to 345
Calculation steps:
[( 345 - 503 ) ÷ 503] x 100 = -31.41%
Formula
Percentage change = [(345 - 503) / 503] x 100
Subtract the new number by the original number
345 - 503 = -158
-158 ÷ 503 = -0.31411530815109345
-0.31411530815109345 x 100 = -31.41%