Your drop-off makes no sense. My PR is only 15:10 but I ran 15:50 at 40.
I had cardiac issues at 32 bad EKG's and some other issues. I eventually had to have cardiac surgery at 33. I took 6 months off the 17:43 I ran at 34 was right before my 35th birthday and my cardiologist advised against over doing it. My original plan was to keep my sub 5:00 streak going but gave it up due to cardiac concerns.
As I mentioned above I did have cardiac surgery. This is the reason why I don't over do it. A couple of years back post surgery I would occasionally hammer a mile under 5:00 and it lead to nothing but hospital visits and serious chest pain. I did lower my annual 5K time today to a still what everyone would call slow 19:09. Overall I just try and run to feel good. I was not looking for crazy negativity on this. For those that are negative I get it I ran 14:17 and my times are not fast compared to my best but I hope you never have to find your groove after cardiac surgery it is a different ball park when it comes to pushing yourself.
My Splits:
1 Mile: 5:59.00
2 Miles: 12:10.00
3 Miles: 18:29.00
5K: 19:09.00 (I did honestly feel like I could have run close to a minute 30 faster is I really wanted to push).
Overall I just try and run to feel good. I was not looking for crazy negativity on this.
Then why do you even ask whether it is good or not? Just be happy with your running without worrying about whether your time looks "good" to others.
Its primarily just about community the problem people have become stuck in a cycle of misery over the past few years I was originally just trying to make conversation. Maybe seeing if anyone else is keeping some kind of a streak going.