-98.19% is the change from 828 to 15
Calculation steps:
[( 15 - 828 ) ÷ 828] x 100 = -98.19%
Formula
Percentage change = [(15 - 828) / 828] x 100
Subtract the new number by the original number
15 - 828 = -813
-813 ÷ 828 = -0.9818840579710145
-0.9818840579710145 x 100 = -98.19%