to decline /dɪˈklaɪn/ /dɪˈklaɪn/
to drop /drɑːp/ /drɒp/
to decrease /dɪˈkriːs/ /dɪˈkriːs/
to diminish /dɪˈmɪnɪʃ/ /dɪˈmɪnɪʃ/
to reduce /rɪˈduːs/ /rɪˈdjuːs/