Slc500 mtbf

Can anyone point me towards some failure rate data for SLC500 modules. I think I used to have some, but now I need it, I can't find it. I found some data for ControlLogix on Rockwell's website, but I can't find anything for the SLC. There ought to be some good data for a system thats been around that long.

I think it's information that you'll have to call Rockwell to get. I remember looking for it a couple months ago, all that could be found on their site was the expected lifetime of relay outputs.