-73.68% is the change from 817 to 215
Calculation steps:
[( 215 - 817 ) ÷ 817] x 100 = -73.68%
Formula
Percentage change = [(215 - 817) / 817] x 100
Subtract the new number by the original number
215 - 817 = -602
-602 ÷ 817 = -0.7368421052631579
-0.7368421052631579 x 100 = -73.68%