-17.86% is the change from 420 to 345
Calculation steps:
[( 345 - 420 ) ÷ 420] x 100 = -17.86%
Formula
Percentage change = [(345 - 420) / 420] x 100
Subtract the new number by the original number
345 - 420 = -75
-75 ÷ 420 = -0.17857142857142858
-0.17857142857142858 x 100 = -17.86%