Worldwide, TV viewing remains the single biggest media activity. On average, 2.58 hours per day are consumed globally, according to London-based GlobalWebIndex’s recent Media Consumption report. That's 23% of total time spent on the media. The U.S. remains the biggest TV market, with an average of 4.33 hours a day. Those in China watch the least TV overall, at 2.2 hours. Online TV viewing continues to rise -- now at 0.7 hours a day. That's a 6% share of all media time. Online viewing now accounts for 33% of total TV time among 16- to-24-year-olds. This compares with 7% for people on the other end of the age spectrum -- 55- to-64-year-olds. China watches the most TV online -- at 1.03 hours a day. U.S. Internet users watch just under one hour a day of TV online. Mobile usage now accounts for 30% of the time we spend on online media -- an increase from 22% in 2012. Those 16 to 24 are the biggest consumers of media via the mobile Internet -- at 2.77 hours per day, up from 1.88 in 2012. The report is culled from a global sample size of more than 40,000 Internet users in 32 countries.