-22.58% is the change from 660 to 511
Calculation steps:
[( 511 - 660 ) ÷ 660] x 100 = -22.58%
Formula
Percentage change = [(511 - 660) / 660] x 100
Subtract the new number by the original number
511 - 660 = -149
-149 ÷ 660 = -0.22575757575757577
-0.22575757575757577 x 100 = -22.58%