66% is the change from 597 to 991
Calculation steps:
[( 991 - 597 ) ÷ 597] x 100 = 66%
Formula
Percentage change = [(991 - 597) / 597] x 100
Subtract the new number by the original number
991 - 597 = 394
394 ÷ 597 = 0.6599664991624791
0.6599664991624791 x 100 = 66%