I'm starting to learn more about beer terms, and I have a question about attenuation. I understand that its the amount of sugars converted by the yeast, but it seems like some yeasts go far beyond the attenuation %. For instance, I made a bitters using a low attenuation yeast (wyeast 1469 67-71%). However, the final gravity dropped to 1.006 from OG 1.043, which is a large drop. What am I not understanding? If it helps, it was the Innkeeper extract kit from NB.