-98.03% is the change from 661 to 13
Calculation steps:
[( 13 - 661 ) ÷ 661] x 100 = -98.03%
Formula
Percentage change = [(13 - 661) / 661] x 100
Subtract the new number by the original number
13 - 661 = -648
-648 ÷ 661 = -0.9803328290468987
-0.9803328290468987 x 100 = -98.03%