fall off
US /fɔːl ɔːf/
UK /fɔːl ɔːf/

1.
cair, diminuir
to decrease in quantity or quality; to decline
:
•
Sales tend to fall off during the winter months.
As vendas tendem a cair durante os meses de inverno.
•
His performance has started to fall off recently.
O desempenho dele começou a cair recentemente.