Did Mr.Mime's egg distance change?

Hi.

I wonder, if Mr.Mime's egg distance was 5 km in the past. 'cause I definetely remember, that I got it from the 5km egg. And at least two charts I trusted show the same (see the image below and this one: https://img-fotki.yandex.ru/get/50666/95829571.146/0_1768eb_4c51806e_XL.jpg). And other regional pokemons come from 5km eggs too.

But on the serebii.net and here it's said Mime comes from 10km eggs, and everybody I asked say the same.

So is it possible, that Mr.Mime distance chainged in the past, and these tables are simply too old, and my Mr.Mime hatched just before this?