911.11% is the change from 9 to 91
Calculation steps:
[( 91 - 9 ) ÷ 9] x 100 = 911.11%
Formula
Percentage change = [(91 - 9) / 9] x 100
Subtract the new number by the original number
91 - 9 = 82
82 ÷ 9 = 9.11111111111111
9.11111111111111 x 100 = 911.11%