Auto sales: 16.5 million
Bike sales: 18.2 million
Auto sales: https://www.businessweek.com/autos/content/jan2007/bw20070104_555558.htm?chan=autos_autos+index+page_news
Bike sales: https://nbda.com/page.cfm?PageID=34
Related artical:
https://www.baltimorespokes.org/article.php?story=20050804154831497oldId.20080116212338373
Biking in Baltimore