-29.88% is the change from 917 to 643
Calculation steps:
[( 643 - 917 ) ÷ 917] x 100 = -29.88%
Formula
Percentage change = [(643 - 917) / 917] x 100
Subtract the new number by the original number
643 - 917 = -274
-274 ÷ 917 = -0.29880043620501634
-0.29880043620501634 x 100 = -29.88%