-98.18% is the change from 661 to 12
Calculation steps:
[( 12 - 661 ) ÷ 661] x 100 = -98.18%
Formula
Percentage change = [(12 - 661) / 661] x 100
Subtract the new number by the original number
12 - 661 = -649
-649 ÷ 661 = -0.9818456883509834
-0.9818456883509834 x 100 = -98.18%