19.4% is the change from 536 to 640
Calculation steps:
[( 640 - 536 ) ÷ 536] x 100 = 19.4%
Formula
Percentage change = [(640 - 536) / 536] x 100
Subtract the new number by the original number
640 - 536 = 104
104 ÷ 536 = 0.19402985074626866
0.19402985074626866 x 100 = 19.4%