-78.49% is the change from 423 to 91
Calculation steps:
[( 91 - 423 ) ÷ 423] x 100 = -78.49%
Formula
Percentage change = [(91 - 423) / 423] x 100
Subtract the new number by the original number
91 - 423 = -332
-332 ÷ 423 = -0.7848699763593381
-0.7848699763593381 x 100 = -78.49%