This is the text from a response, which covers the numbers question in part. You need to start visiting the sites mentioned if you want to know the details. With 122 lenses listed on the Canon Museum site and a further 65 on their current website, it is clearly not something that would be simple to answer!
Extract from CanonFD Forum entry:
I have done a quick count of lenses on the Canon Camera Museum site (http://www.canon.com/camera-museum/camera/lens/f_lens.html) and the Nikon System Handbook 6th Edition (2000) by B. Moose Peterson. For Canon:
EF - 45 prime, 8 EFS, 77 zoom
FDnew 42 prime, 23 zoom
FEold 59 prime, 6 zoom
FL 30 prime, 3 zoom
R 20
S 69
Total 382 plus a few specials such as the EE lenses covering the period from 1950 to 2005.
Nikon F mount - 207 lenses listed in the Nikon System Handbook covering the period 1959-1999.
On their current (Australian) websites, Canon list 65 lenses, Nikon list 48 and Pentax list 17 lenses.
Tamron list 26 lenses in their current catalog.
Tokina list 14 lenses on their website, but only six in their catalog. The four/thirds system partners (Olympus, Sigma, Panasonic) list 28 lenses on the 4/3 website.
While Nikon's F mount has the highest number of distinct lenses, this covers three major generations of manual focus lenses (pre-AI, AI, AI-S) and five major generations of auto focus film lenses (AF, AF-D, AF-I/AF-S, G, VR). Up until the G lenses, with some minor exceptions, every newer lens could be used on any older body, but not vice versa.
Canon manual focus bayonet mount cameras would have had about 163 distinct lenses available (FDnew, FDold, FL) compared to a potential 207 plus for Nikon of the same generation.
Clearly Nikon and Canon stand out from the rest of the field in terms of the shear number of models that have and continue to make. Canon has an edge in current models, but clearly you could run the argument either way for their previous models.
DougF