GO!
This clue is encrypted with a LETTER NUMBERS cipher. That means each number equals the number letter it is on the alphabet. i.e. A = 1, B = 2, Y = 25, Z = 26. There are dashes between letters and spaces between words.
20-08-05 17-21-09-20-20-05-18 15-06 19-05-01-19-15-14 06-15-21-18
