-2.38% is the change from 841 to 821
Calculation steps:
[( 821 - 841 ) ÷ 841] x 100 = -2.38%
Formula
Percentage change = [(821 - 841) / 841] x 100
Subtract the new number by the original number
821 - 841 = -20
-20 ÷ 841 = -0.023781212841854936
-0.023781212841854936 x 100 = -2.38%