-21.38% is the change from 650 to 511
Calculation steps:
[( 511 - 650 ) ÷ 650] x 100 = -21.38%
Formula
Percentage change = [(511 - 650) / 650] x 100
Subtract the new number by the original number
511 - 650 = -139
-139 ÷ 650 = -0.21384615384615385
-0.21384615384615385 x 100 = -21.38%