This study by "Yoga Journal" magazine from 2012 was the latest study I found on the growth of Yoga. I thought it had enough good data about Yoga to still post it for your viewing. From what I keep hearing, Yoga continues to maintain it's popularity as it grows.
"Yoga in America Study 2012
Number of practitioners increases to 20.4 million, while practitioner spending grows to $10.3 billion a year
Yoga Journal Releases 2012 "Yoga in America" Market Study
SAN FRANCISCO – The latest "Yoga in America" study, just released by Yoga Journal (yogajournal.com) shows that 20.4 million Americans practice yoga, compared to 15.8 million from the previous 2008 study*, an increase of 29 percent. In addition, practitioners spend $10.3 billion a year on yoga classes and products, including equipment, clothing, vacations, and media. The previous estimate from the 2008 study was $5.7 billion*.
Data for this survey, the most comprehensive study of the consumer yoga market available, were collected by Sports Marketing Surveys USA on behalf of Yoga Journal.
The 2012 study indicates that 8.7 percent of U.S. adults, or 20.4 million people, practice yoga. Of current non-practitioners, 44.4 percent of Americans call themselves "aspirational yogis"—people who are interested in trying yoga.
"The number of practitioners and the amount they spend has increased dramatically in the last four years," says Bill Harper, vice president and group publisher of Active Interest Media's Healthy Living Group. "Companies that want to advertise to the health-and-fitness market for women will want to make sure that yoga is a strong segment in their target."
The study also collected data on age, gender, and other demographic and lifestyle factors. Of the yoga practitioners surveyed:
Gender: 82.2 percent are women; 17.8 percent are men.
Age: The majority of today's yoga practitioners (62.8 percent) fall within the age range of 18-44.
Length of practice: 38.4 percent have practiced yoga for one year or less; 28.9 percent have practiced for one to three years; 32.7 percent have practiced for three years or longer.
Level of practice: 44.8 percent consider themselves beginners (22.9 percent are new to yoga; 21.9 percent are beginning to practice yoga after taking some time off); 39.6 percent consider themselves intermediate; 15.6 percent consider themselves expert/advanced.
Motivation for practice: The top five reasons for starting yoga were: flexibility (78.3 percent), general conditioning (62.2 percent), stress relief (59.6 percent), improve overall health (58.5 percent) and physical fitness (55.1 percent).
The growth in the yoga market is reflected in the growth of Yoga Journal magazine, which recently announced a rate-base increase to 375,000 from 350,000 effective January 2013..."
*Study conducted by Harris Interactive Service Bureau.