There is more smoking in TV shows rated TV-PG than in TV shows with a TV-14 rating. In other words, smoking is more prevalent on shows that aim to reach younger viewers. Hmm.
Cullen, Jennifer, et al. "Depictions of Tobacco Use in 2007 Broadcast Television Programming Popular Among US Youth." Archives of Pediatric and Adolescent Medicine. 165(2). 07 Feb. 2011: 147-151. Web.