-3.38% is the change from 591 to 571
Calculation steps:
[( 571 - 591 ) ÷ 591] x 100 = -3.38%
Formula
Percentage change = [(571 - 591) / 591] x 100
Subtract the new number by the original number
571 - 591 = -20
-20 ÷ 591 = -0.0338409475465313
-0.0338409475465313 x 100 = -3.38%