-73.57% is the change from 821 to 217
Calculation steps:
[( 217 - 821 ) ÷ 821] x 100 = -73.57%
Formula
Percentage change = [(217 - 821) / 821] x 100
Subtract the new number by the original number
217 - 821 = -604
-604 ÷ 821 = -0.7356881851400731
-0.7356881851400731 x 100 = -73.57%