From the FAA's web site on pilot statistics. There are currently over 262,000 active licensed commercial and ATP pilots today with valid medicals. over 80,000 of them are CFI's. For every pilot who holds a medical there are at least 4 more who quit and let it lapse. The numbers on uncounted commercial pilots is staggering. The odds of making to a major airline are at least one in 25.
http://www.faa.gov/data_statistics/a...ia/air1-05.xls
Who knows how many failed military pilots are out there who never got a civilian license.
SkyHigh