This is from Bryan Caplan. Full post is worth reading:
If you peruse this table, you’ll discover that total number of new M.D.s per year has been virtually flat for 30 years. During this period, population increased over 30%. As a result, the new M.D./population ratio has declined for decades.
If you’re not horrified, consider that the senior population ― doctors’ best customers ― increased by over 50%. As a result, new M.D.s per senior fell by about a third over the last three decades.