Trying to predict where the stock market will be in 12 months, let alone five or 10 years out, is at best an imprecise science, at worst a fool’s errand.

Still, it’s hard to resist the temptation, especially at year’s end. And especially with some eye-opening census data about the entertainment biz that has just been made available.

Americans are getting fatter, building bigger houses, drinking more mineral water, even praying more, but it is astounding to learn just how much media they are now consuming. More even than gas to fill their SUVs!

Latest stats suggest that Americans routinely spend eight-plus hours a day variously watching television, going to the movies, surfing the Internet, listening to the radio, playing music or reading books or newspapers.

Teenagers and adults averaged more than two months a year glued to the small screen, 41 days tuned to the radio and an entire week using the Internet.

Some 97 million users clicked onto the Internet in search of the news during the year, 92 million bought something online, 91 million made a travel reservation, 16 million checked out a professional or social networking site and 13 million created their own blog.

The data supports what we all know by now: The online component of our leisure time is on a rising trajectory, while TV viewing, not to mention reading, is waning.

Online upstarts and digital gizmos have unsettled or upended old media, forcing them to scramble to update their businesses. Upended or unsettled, yes. But emptied of value the old media is not.

Take the current Christmas ads: The little lady of the house runs right past those sparkling diamonds from Zales to tear open that box from Best Buy with a sparkling liquid crystal TV screen inside.

In theory all this should be good news for those involved in media and entertainment: The world can’t get enough of this stuff. As for those wishing to invest in the sector, I’d imagine there are a lot of undervalued oldline companies out there.

Oddly though, Wall Street looks more askance at media than at almost any sector you can name: Investment research outfit Morningstar reports the sector lost almost 6% in value overall compared to 5% for those maligned tech hardware stocks during the past five years.

The challenges for media, however, are not unlike those of many other industries.

Earlier census data this decade revealed the extent of our obsession with and spending on health care and medical services. And with soon-to-retire boomers likely to be even bigger users of pills and procedures than previous generations, you would have thought that sector was on a tear.

But no, the health-care sector has not performed well of late, with a number of scandals plaguing the industry and several hoped-for breakthroughs not panning out.

Most analysts caution investors not to place their bets on any one drug company or medical equipment maker or insurer — even Pfizer recently took a notable hit in its stock price.

In that respect the FDA turning a thumbs-down on a new cholesterol drug from Pfizer is not unlike an opening-weekend disaster at the B.O. As an investor, you would have to do constant homework to avoid a hit like that on an individual stock.

In other words, to put your chips on a Time Warner rather than Disney, News Corp. rather than Liberty Global, Lionsgate rather than DreamWorks Animation, or Clear Channel rather than Tribune is not a bet for the fainthearted.

Better there were more mutual funds that targeted the sector as a whole.

Several do weight certain of their funds more heavily toward media than does, say, the S&P 500 (which includes a dozen media stocks but only for roughly 4% of the weighted total).

Mario Gabelli has his Global Multimedia Trust Fund (GGT), which used to be the amusingly named “couch potato” fund and is now closed-end and trades at a 13% discount, while Fidelity offers a Select Leisure Portfolio and T. Rowe Price boasts a Media & Telecommunications Fund; Weitz Value Fund and the Oakmark Fund also give ample play to media stocks, including Liberty Media, DirecTV and Time Warner.

All these funds are noticeably up for the year, as much as 28% for the T. Rowe Price fund.

It’s something to think about when toying with how to spend that year-end bonus.