More than four out of five U.S. teenagers now own an iPhone, and that number is growing, according to the latest results from a large-scale survey.

Back in the spring of 2014, the percentage was at 60% – it’s now at 82% and looks set to increase further …

Piper Jaffray has run its twice-yearly Teens Survey for four years now, and Business Insider reports that the percentage who own an iPhone has grown from 78% in the fall of last year to 82% today.

The good news for Apple doesn’t end there.

That could, suggests the firm, indicate great prospects for this year’s iPhone line-up.

The enduring popularity of the iPhone in America’s high schools may also be leading to a boom in Apple Watch interest. 20% of teens plan to buy an Apple Watch in the next 6 months, and Apple is the 2nd-most desired brand among upper-income teens, behind only Rolex, according to the survey.

The survey is run among thousands of teenagers across 40 states.

A smaller-scale survey recently suggested that upgrade rates are stabilising, and that ‘annual iPhone growth will settle into a more predictable 1-5% range.’