The US Centers for Disease Control and Prevention tracks onscreen smoking the same way that it tracks cholera outbreaks. Check out CDC's summary of kids' exposure to movie smoking, in 2017, on its latest Smoking in the Movies fact sheet — and pass it along.
One conclusion:
"An R rating for movies with tobacco use can potentially reduce the number of teen smokers by 18%, preventing up to 1 million premature smoking deaths among youth alive today."
Want to go deeper? You'll find CDC fact sheets, with data back to 2012, archived here. For additional tobacco data on 2017 movies, view this Breathe California-UCSF report.