The proportion of Americans who use the Internet appears to have peaked over the past few years. Around one in five of the adult population doesn’t use it, and many see no point in doing so. It could prove barrier to shifting more public services and private business online.

The Pew Internet & American Life Project has been tracking net use since 1995 when just 14 percent of adults were online. That shot up through the rest of the decade, hitting the 50 percent mark in 2000 and 73 percent by 2006. Since then it has hovered up and down by a few percent (suggesting statistical quirks as much as behavioral changes) with newly-published figures for last August showing a rate of 78 percent.

As is a common theme, being white and male makes you more likely to be online, though the gaps for both gender and race are closing rapidly. (In the case of black and Hispanic users, previous surveys have suggested being able to access the Internet on a phone rather than a computer is making a big difference.)

Age, education and household income are now the key factors: there’s a consistent pattern that the younger, better-paid and more-educated you are, the more likely you are to be online. While 43 percent of adults without a high school diploma are online, the figure is 94 percent for college graduates. That may be cultural as much as the education itself: it seems virtually impossible to imagine that anyone who has been to college in the past few years has never used the Internet.

One development is that a majority (54 percent) of adults with a disability are now online, though this still remains far short of the 81 percent figure for adults without a disability.

The survey also looked at changes in why people aren’t online. Amazingly in the 2000 version of the survey, a majority of the “internots” believed the net was “a dangerous thing”, an option the survey conductors didn’t even ask about this time.

Instead, when asked to give a single main reason in a 2010 Pew survey, almost a third said they simply weren’t interested, with the other leading reasons being not having a computer, getting online being too expensive, and it being too difficult. When the various individual reasons are (somewhat roughly) combined, around one in four believe they can’t get online for various reasons, one in four say price is a problem, and just under half simply aren’t interested under any circumstances.

While that means around 10 percent of the population is highly unlikely to get online any time soon, that still leaves room for growth even without waiting for the inevitable increase in net use as elderly refusers die out. One route may be through mobile devices: Pew found that once people get internet access on a mobile device, they begin to carry out more activities online, even on desktop computers as well.