51.5% is the change from 266 to 403
Calculation steps:
[( 403 - 266 ) ÷ 266] x 100 = 51.5%
Formula
Percentage change = [(403 - 266) / 266] x 100
Subtract the new number by the original number
403 - 266 = 137
137 ÷ 266 = 0.5150375939849624
0.5150375939849624 x 100 = 51.5%