To tell if an older vintage is still drinkable, use the same technique you would use to judge any wine.
Look at the space between the cork and the wine. If your old bottle has more space than it should, there’s a good chance the wine has oxidized, evaporated or seeped out through the cork.
Then, bring the wine to the correct drinking temperature, open it, pour, swirl and smell. If it smells good, taste a little. If you like it, it’s good and can be served.