How long does Crataegus laevigata 'Crimson Cloud' live on average?

I've been looking all over online. I've found a couple of sources that say 15-20 years, one said 25-50 years, one that might have said 100 years+ (it was unclear), and one that made the general statement that hawthorn trees can easily survive several centuries.

15-20 years seems ridiculously short-lived. I have two in my yard that are currently at least 5 years old (I got them from a nursery 2 years ago, and they've been flowering since I got them). I like them a lot, but they're still very scrawny and only about 7 feet tall. Are they really only going to be around for 10-15 more years? If that's the case, it sounds like I'll be lucky if they make it to full size before they're expected to go.

Does anyone have any experience with Midland/English Hawthorns? Thanks in advance!