8 fall off

fall off
decrease in quantity or quality 数量或质量下降
    Attendance at my lectures has fallen off considerably. 听我讲课的人已大大减少了.
    It used to be my favourite restaurant but the standard of cooking has fallen off recently. 那是我以前最喜欢的饭馆, 但近来烹饪水平已大不如前了.