I also think you indexed rate is quite good. One half of my books are not even in EYB, because they are not in English - out of those I have listed in EYB about 45% are indexed so far -even so I find EYB is a great for finding the recipes I want.
The good thing about EYB is that books get indexed all the time. If you look in the library you will find the books below in the recent 25 indexed books:
The Sprouted Kitchen: A Tastier Take on Whole Foods
A Vegan Taste of Central America
A Vegan Taste of France
2 of these books are indexed by an EYB member. So if one of your favorite books dont get indexed by EYB , you could do it yourself.
Another good thing about EYB is that you can "take a look" at the recipes in books you are interested in to see if they have recipes that interest you (great if you buy books online)
Have you noticed that you can add blogs and magazines to you bookshelf? That way you will have access to more recipes.
There are 6454 vegan / 18414 vegetarian online recipes in the library. You can add online recipes individually to you own book shelf.