68.37% is the change from 392 to 660
Calculation steps:
[( 660 - 392 ) ÷ 392] x 100 = 68.37%
Formula
Percentage change = [(660 - 392) / 392] x 100
Subtract the new number by the original number
660 - 392 = 268
268 ÷ 392 = 0.6836734693877551
0.6836734693877551 x 100 = 68.37%