The decline is particularly sweet because it comes after a decade of relatively stable smoking levels when "we just weren't able to turn the tide," said Giridhar Mallya, the Health Department's director of policy and planning.
Studies have backed the city's approach, especially raising cigarette prices.
But Schwarz said the city is constrained by state limits on cigarette prices. Raising those would be the easiest way to drive further decline, he said.
So the city attacks smoking through other avenues, such as decreasing "the amount of acreage" available for smokers.
The news conference was held at the Restaurant School at Walnut Hill College, which Schwarz praised for becoming the city's first (and only) college to ban smoking. The ban caused complaints, president Daniel Liberatoscioli said, but was worth it.
Schwarz said getting more groups to ban smoking is the next battlefront.
More than 200 city recreation centers and playgrounds are now smoke-free, and a city antismoking campaign was seen or heard 24 million times.
The state Department of Health offers free smoking cessation counseling and eight weeks of free nicotine patches via "Quitline" at 1-800-QUIT-NOW (1-800-784-8660).
The result, Mallya said, is a decline in smoking across all racial, socio-economic, and gender groups.
Thirty of the nation's 50 most populous cities prohibit smoking indoors in all private workplaces, restaurants, and bars, the Centers for Disease Control and Prevention also announced Thursday.
In 2000, only one city, San Jose, Calif., had such a law, the CDC said.
Still, smoking remains the No. 1 cause of death across the nation, including in Philadelphia.
"I want to make sure people are aware of the risks they're taking," Schwarz said, citing the threat of secondhand smoke. "It's not a wise choice."
Contact Jonathan Lai at 215-854-5151, firstname.lastname@example.org, or on Twitter @elaijuh.