-23.8% is the change from 664 to 506
Calculation steps:
[( 506 - 664 ) ÷ 664] x 100 = -23.8%
Formula
Percentage change = [(506 - 664) / 664] x 100
Subtract the new number by the original number
506 - 664 = -158
-158 ÷ 664 = -0.23795180722891565
-0.23795180722891565 x 100 = -23.8%