grammaticality - Why is this sentence correct?

In 2005, fiction made up the largest proportion of items borrowed at 35% with children's books and DVDs equally second at 20% each.

I have two question about this.

1. The preposition with is followed by a clause without a verb, so why is this sentence correct?


2. Has an of been elided in "20% each"? Does it correspond to "20% of each"?