Inner length:

21 yards long, 13.5cm

22 yards long, 14cm

23 yards long, 14.5cm

24 yards long, 15cm

25 yards long, 15.5cm

26 yards long, 16cm

27 yards long, 16.5cm

28 yards long, 17cm

29 yards long, 17.5cm

30 yards long, 18cm