-84.7% is the change from 647 to 99
Calculation steps:
[( 99 - 647 ) ÷ 647] x 100 = -84.7%
Formula
Percentage change = [(99 - 647) / 647] x 100
Subtract the new number by the original number
99 - 647 = -548
-548 ÷ 647 = -0.8469860896445132
-0.8469860896445132 x 100 = -84.7%