1761.9% is the change from 21 to 391
Calculation steps:
[( 391 - 21 ) ÷ 21] x 100 = 1761.9%
Formula
Percentage change = [(391 - 21) / 21] x 100
Subtract the new number by the original number
391 - 21 = 370
370 ÷ 21 = 17.61904761904762
17.61904761904762 x 100 = 1761.9%