Ordinal numbers

123456789101112131415161718
Across
  1. 2. 5th
  2. 3. 3rd
  3. 6. 22nd
  4. 9. 10th
  5. 11. 31st
  6. 13. 12th
  7. 15. 9th
  8. 16. 17th
  9. 18. 4th
Down
  1. 1. 13th
  2. 4. 7th
  3. 5. 8th
  4. 7. 4th
  5. 8. 16th
  6. 10. 20th
  7. 12. 2nd
  8. 14. 1st
  9. 16. 6th
  10. 17. 14th