infrequency

/ɪnˈfrikwənsi/
noun
  1. The quality or state of happening rarely or not often; rarity of occurrence.
    • The infrequency of train delays on this line makes it very reliable.
    • Due to the infrequency of his emails, she was surprised to receive one today.
    • The infrequency of snowfall in this coastal city means residents rarely see snow.