Insulin ratios can change because of all sorts of things, weight change, exercise change, stress change, hormones, weather and yes I guess age too. I don't expect mine to stay the same so if I think it isn't right any more I tweak it until I'm happy.
Of course, you should ask your medical team, we are not doctors etc etc, but I've always worked on the principal that I change my insulin when I think it needs changing and then take advice from the team if they disagree when I next see them....
Good luck.