mikemax@mmax:~$ cat cal.txt | grep -E '^(\w{2}|\w{2}\/\w{2})$' | sort -n | uniq -c
     66 AP
      1 AP/DL
      4 AP/JL
     48 DL
     59 GM
     48 JL
     66 KS
      4 KS/DL
      1 KS/GM
     65 NH