Inner length:

21 yards long, 13cm,

22 yards long, 13.5cm

23 yards long, 14cm

24 yards long, 14.5cm,

25 yards long, 15cm

26 yards long, 15.5cm

27 yards long, 16cm

28 yards long, 16.5cm

29 yards long, 17.5cm

30 yards long, 18cm