A mere 9.1 percent of American retailers sold tobacco to youth under the age of 18 in 2012, according to an annual survey by the U.S. Substance Abuse and Mental Health Services Administration (SAMHSA).
SAMHSA has published the Synar Report — named after the late public health advocate and former Democratic congressman Rep. Mike Synar (OK) — every year since 1997. The survey tracks each state’s findings on the number of stores selling tobacco to minors by using a combination of random audits and undercover youth inspectors who test whether or not merchants are hewing to cigarette age restrictions. Stores’ noncompliance rates have been plummeting ever since the states and SAMHSA started collecting data on their behavior, dropping by a staggering 77.25 percent over the last 15 years.
Here's a link to the report.