There are 42 possible numbers: every number between 2 and 43, inclusive.
The most frequent numbers are those from 13 to 30 - they will occur
once every month of every year.
The most infrequent numbers are 2, 42, and 43. Each occurs only once a year:
2 on January 1st, 42 on December 30th, and 43 on December 31st.