3394.74% is the change from 19 to 664
Calculation steps:
[( 664 - 19 ) ÷ 19] x 100 = 3394.74%
Formula
Percentage change = [(664 - 19) / 19] x 100
Subtract the new number by the original number
664 - 19 = 645
645 ÷ 19 = 33.94736842105263
33.94736842105263 x 100 = 3394.74%