'Unidentified viewing' - including streaming services like Netflix - accounts for nearly 20% of UK TV viewing

"In the 12 months to September 2018, time spent on unidentified viewing – where the TV set was being used to do something other than watch a BARB-reported channel or on-demand service – increased to 19 per cent of all TV set activity, up from 16 per cent in the preceding 12 months. In minute terms, that is a rise from 40 to 46 minutes a day on average."

Source:  Advanced Television, citing data from BARB, 24th January 2019