Working life. You may have heard about the cervical screening programme that has been very successful and has significantly reduced the incidence of cervical cancer since it started in 1998.
24.8 cm = size 7. 25.4 cm = size 7.5. 25.7 cm = size 8. 26.0 cm = size 8.5. 26.7 cm = size 9. 27.0 cm = size 9.5. 27.3 cm = size 10. 27.9 cm = size 10.5. Roughly speaking, the shoe size goes up one size for each additional centimeter in length.
The average size for a 12 month old shoe is around a 3, my son's first shoes were a 6 at 12 months. So it's really hard to say what size shoes a 12-18 month old would need, as they're all diferent and all grow so fast.