-29.05% is the change from 902 to 640
Calculation steps:
[( 640 - 902 ) ÷ 902] x 100 = -29.05%
Formula
Percentage change = [(640 - 902) / 902] x 100
Subtract the new number by the original number
640 - 902 = -262
-262 ÷ 902 = -0.29046563192904656
-0.29046563192904656 x 100 = -29.05%