-9.61% is the change from 666 to 602
Calculation steps:
[( 602 - 666 ) ÷ 666] x 100 = -9.61%
Formula
Percentage change = [(602 - 666) / 666] x 100
Subtract the new number by the original number
602 - 666 = -64
-64 ÷ 666 = -0.0960960960960961
-0.0960960960960961 x 100 = -9.61%