Schramsberg 2006 Blanc de Blancs I’ve had for a few years. I’m clueless when it comes to wine, and don’t know how long champagne lasts. Can anyone clue me in?

Schramsberg 2006 Blanc de Blancs I’ve had for a few years. I’m clueless when it comes to wine, and don’t know how long champagne lasts. Can anyone clue me in?