100.38% is the change from 260 to 521
Calculation steps:
[( 521 - 260 ) ÷ 260] x 100 = 100.38%
Formula
Percentage change = [(521 - 260) / 260] x 100
Subtract the new number by the original number
521 - 260 = 261
261 ÷ 260 = 1.0038461538461538
1.0038461538461538 x 100 = 100.38%