Everything's fine. Only "Eleventh" should be concise.
Just like "Sixteen" in "Sixteen Years Old", it is concise and lively.
Therefore, the number 1 1- 19 should read:
1 1 pronounced eleven,
12 is pronounced as 12,
13 is pronounced thirteen,
14 is pronounced as 14,
15 is pronounced fifteen,
16 is pronounced as 16,
17 is pronounced seventeen,
18 is pronounced eighteen,
1 9 is pronounced nineteen.