In the UK, and in some other countries too, this has increased as people have got taller and heavier. In 1990 the average shoe size for women was 4 1/2, but it is now a 6 (39 in European sizing), while the average height is now 5 ft 4. Larger shoe sizes are also getting more and more common - not long ago it was hard to find anything over a 7, but now shops stock a lot of size 8 and 9 shoes. You can also find much larger sizes, up to 13 or more.
Wider fitting shoes are also much more generally available now, with many shoe shops offering a special range of wider shoes. Some people in the shoe trade say this is because, rather than getting longer, women's feet are getting wider as they grow heavier.
Although larger feet are now the norm, many women feel embarrassed by them and often prefer to buy shoes online rather than going in a shop and asking for the larger sizes.