Cigarette smoking dropped to an all-time low among American adults in 2018, according to a Center for Disease Control (CDC) report released Thursday. According to the report, 13.7% of U.S. adults smoked a cigarette in 2018.

Since the first Surgeon General’s report warned of the health implications of smoking over 50 years ago, cigarette smoking has declined by approximately two-thirds.

“The sustained drop in adult smoking is encouraging as we work to reduce tobacco-related disease and death in the U.S. through science-driven policy, compliance and enforcement in addition to public education,” said Acting FDA Commissioner Brett Giroir, according to the report.

While more adults may be putting down traditional cigarettes, e-cigarette use increased from 2017, according to the CDC. The uptick was largely due to an increase in e-cigarette use among young adults aged 18 to 24, from 5.2% in 2017 to 7.6% in 2018.

The increase in young people using e-cigarettes in 2018 preceded the spike of vaping-related illnessesAs of Wednesday, 2,172 cases of “e-cigarette, or vaping, product use associated lung injury” have been reported to the CDC from 49 states, as well as Washington D.C. and two U.S. territories. Forty-two deaths have been confirmed to the organization.

An estimated 49.1 million American adults, or 19.7% percent of the population, reported using any type of tobacco product in 2018, the CDC said. Cigarettes continued to be the most commonly used product, followed by cigars, cigarillos, or filtered little cigars at 3.9%. E-cigarette use clocked in at 3.2%.

Adults ranging from 25 to 44 years old used  tobacco at relatively high rates, according to the report. Income also appeared to be a risk factor — those with an annual household income below $35,000 also used tobacco at relatively higher rates, the report said.