Average age to start laying for certain breeds?

[blurose]

Here is a list of the 26-week old pullets that I have. I know that only 6-7 of them are laying currently. I have 34 of these pullets and consequently feel I should be getting a lot more eggs per day. Can those of you in the know please offer an opinion on the age that each of these breeds should be starting to lay? I've got 5 white egg layers but only get 3 white eggs a day, and I'm certain that only one of my EE is currently laying.

Barnevelder
Welsummer
Cuckoo Maran
Partridge Wyandott
Partridge Chanteclar
Partridge Rock
Brown Leghorn--already laying, I'm certain
Ancona--maybe already laying
Golden Brabantar--maybe already laying
Speckled Sussex
Black Australorp
Spangled Russian Orloff

 

[RAREROO]

From your list I have only had experience with speckled Sussex and they started laying around the normal six mos, A Barred Rock laid her first egg 5 mos to the day that I recieved her as a 3 day old chick, but these girls started laying during the spring, the colder weather we are getting now can cause tham to start later.
I also have 2 EE hens that started around five mos, but I have had so hens go all the way to 9 mos before they started.

 

[Ridgerunner]

I'm not convinced there is a meaningful average age to start laying, let alone by breed, especially for hatchery stock. I keep reading on here that Buff Orps don't lay until they are 26 weeks, yet I had three of 7 laying by 20 weeks, one of them at 18 weeks. The one that started laying at 18 weeks is not going to be a keeper either. She lays irregularly and lays a lot of double yolk eggs. I consider that makes her more likely to be eggbound or to prolapse. I prefer those that lay a regular egg regularly even if I have to wait a bit on them to start.