rows linking to a LIVE course node : 20583
rows whose course nid is gone      : 286
rows with a non-numeric value      : 4
total cid-30 rows                  : 20873
submissions on node 27             : 21064
submissions with NO course value   : 191

unresolvable values:
  non-numeric: (4)
  nid 10 (5 rows)
  nid 168 (7 rows)
  nid 349 (141 rows)
  nid 382 (131 rows)
  nid 91 (2 rows)