-66.92% is the change from 668 to 221
Calculation steps:
[( 221 - 668 ) ÷ 668] x 100 = -66.92%
Formula
Percentage change = [(221 - 668) / 668] x 100
Subtract the new number by the original number
221 - 668 = -447
-447 ÷ 668 = -0.6691616766467066
-0.6691616766467066 x 100 = -66.92%