-98.2% is the change from 666 to 12
Calculation steps:
[( 12 - 666 ) ÷ 666] x 100 = -98.2%
Formula
Percentage change = [(12 - 666) / 666] x 100
Subtract the new number by the original number
12 - 666 = -654
-654 ÷ 666 = -0.9819819819819819
-0.9819819819819819 x 100 = -98.2%