-33.78% is the change from 521 to 345
Calculation steps:
[( 345 - 521 ) ÷ 521] x 100 = -33.78%
Formula
Percentage change = [(345 - 521) / 521] x 100
Subtract the new number by the original number
345 - 521 = -176
-176 ÷ 521 = -0.3378119001919386
-0.3378119001919386 x 100 = -33.78%