"seriously decline" — Kollokationen-Wörterbuch Englisch

seriously decline Kollokation
Automatische Übersetzung (wir garantieren seine Korrektheit nicht): poważnie upadek
  1. decline Verb + seriously Adverb
    Schwache Kollokation

    That year enrollment in the school seriously declined, and occasionally no students showed up for some of the classes.