The 85% target is aspirational. I'm not sure if there's any air force in the world that is able to achieve that rate of serviceability with their aircraft. That being said, my understanding is that there are multiple factors for this 55% rate, including the impact of COVID: the physical distancing and the restrictions that were in place, where you can't get all the technicians huddled around one aircraft at the same time.
Is the age of the aircraft a factor? Yes, absolutely, but I think the important thing is that we have been able to deliver on operations continually. We've been ready to respond and ready to deploy our aircraft as the need has been there.