Hen Lifespan (text books vs "real life experience")

[Poppins2016]

We have ISA Brown and Light Susex hens (specifying as I know breed affects lifespan).

From the research I did before getting our hens, I know Light Sussex can live up to about 8 years and ISA Browns a little less, however I'm curious to see what people have experienced "in real life" terms...

I'm asking as I want to settle a debate with DH. He reckons we'll have to keep replacing our hens every couple of years whereas I'm more optimistic!

My DH has an old girl(hen) and she is over 12 years old and rules the roost.

Most of my brown hens only lived about 4 years. I had a speckledy that died earlier this year aged 9.

Had a Barnevelder, who was almost 13 when she died, and 2 leghorns who are coming up almost 15!

Ex-batts lasted 3 years at most, speckledy around 6 years, other a mix of passing within weeks to around 5 years. Columbian Blacktails who were wonderful creatures I wish had lasted longer at about 4 years.

I miss my girls

My friend had an 18 year old girl. She even laid once in a blue moon! My oldest is probably about 6. My bigger breeds, like brahmas seem to break easily and die fairly young. The smaller farmyard types seem far tougher.