I recently bought volumes 1, 2, and 3 of the Official Encyclopedia. These are early volumes with pictures of the cards issued up to 4th edition (Volume 1), 5th edition and Mirage block (Volume 2), and Tempest block (Volume 3). I have Volume 4 on the way and it covers Urza block. I believe Volume 5 covers Mercadian Masques, and Volume 6 covers Invasion block.
In Volume 1 there is mention of the print runs that Wizards has made public:
Limited Edition Alpha (August 1993): 2.6 million cards
Limited Edition Beta (October 1993): 7.3 million cards
Unlimited (December 1993):35 million cards
Arabian Nights (December 1993): 5 million cards
Antiquities (March 1994): 15 million cards
Revised (April 1994): many more than Unlimited
The Dark (August 1994): 62 million cards
Fallen Empires (November 1994): more than four times the number issued for The Dark (that is a ton of cards for this early period!)
Legends: 35 million cards