1677.78% is the change from 18 to 320
Calculation steps:
[( 320 - 18 ) ÷ 18] x 100 = 1677.78%
Formula
Percentage change = [(320 - 18) / 18] x 100
Subtract the new number by the original number
320 - 18 = 302
302 ÷ 18 = 16.77777777777778
16.77777777777778 x 100 = 1677.78%