What's the prognosis for mild COPD?

I am a 60 year old man with very mild COPD (Chronic Obstructive Pulmonary Disease) according to my doctor. My last chest x-ray showed no active COPD from my last x-ray one year ago. The only symptom I have is a little mucous in my throat. I was first diagnosed in 2006. I feel good for a 60 yr old and I only have high blood pressure, which is very well controlled. Could you give me a reasonable prognosis? I am a priest and know that everybody dies from something.