-20.95% is the change from 506 to 400
Calculation steps:
[( 400 - 506 ) ÷ 506] x 100 = -20.95%
Formula
Percentage change = [(400 - 506) / 506] x 100
Subtract the new number by the original number
400 - 506 = -106
-106 ÷ 506 = -0.20948616600790515
-0.20948616600790515 x 100 = -20.95%