29.3% is the change from 645 to 834
Calculation steps:
[( 834 - 645 ) ÷ 645] x 100 = 29.3%
Formula
Percentage change = [(834 - 645) / 645] x 100
Subtract the new number by the original number
834 - 645 = 189
189 ÷ 645 = 0.2930232558139535
0.2930232558139535 x 100 = 29.3%