What comes after primary, secondary, tertiary?

The sequence continues with quaternary, quinary, senary, septenary, octonary, nonary, and denary, although most of these terms are rarely used. There’s no word relating to the number eleven but there is one that relates to the number twelve: duodenary.

1. primary
2. secondary
3. tertiary
4. quaternary
5. quinary
6. senary
7. septenary
8. octonary
9. nonary
10. denary
11. /not exists!/
12. duodenary