-98.05% is the change from 666 to 13
Calculation steps:
[( 13 - 666 ) ÷ 666] x 100 = -98.05%
Formula
Percentage change = [(13 - 666) / 666] x 100
Subtract the new number by the original number
13 - 666 = -653
-653 ÷ 666 = -0.9804804804804805
-0.9804804804804805 x 100 = -98.05%