20 stamps/page * 5 pages. You got 100 stamps in total.
Background:
The flowers pictured on this set of four 34¢ denominated stamps are Freesia, Cymbidium Orchid, Longiflorum Lily, and Asian Hybrid Lily. These non-denominated 34¢ stamps were issued in a self-adhesive format. They were first seen in a non-denominated version issued for the 2000 rate change.
Photographs of the lilies were by Robert Peak, Jr., whose father had designed several U.S. stamps many years previously.