29.5% is the change from 644 to 834
Calculation steps:
[( 834 - 644 ) ÷ 644] x 100 = 29.5%
Formula
Percentage change = [(834 - 644) / 644] x 100
Subtract the new number by the original number
834 - 644 = 190
190 ÷ 644 = 0.2950310559006211
0.2950310559006211 x 100 = 29.5%