Inner length:
21 yards: 13.4 cm 22 yards: 13.8 cm
23 yards: 14.3 cm 24 yards: 14.6cm
25 yards: 15.3 cm 26 yards: 16 cm
29 yards: 17.9cm 30 yards: 18.5 cm
31 yards: 19 cm 32 yards: 19.8 cm
33 yards: 20.5cm 34 yards: 21.3 cm
35 yards: 22cm 36 yards: 22.5cm