67.73% is the change from 251 to 421
Calculation steps:
[( 421 - 251 ) ÷ 251] x 100 = 67.73%
Formula
Percentage change = [(421 - 251) / 251] x 100
Subtract the new number by the original number
421 - 251 = 170
170 ÷ 251 = 0.6772908366533864
0.6772908366533864 x 100 = 67.73%