LOS ANGELES -- Hollywood's holidays are off to a dreadful start: Fewer people went to the movies the past two weekends than during the box-office hush that followed the Sept. 11 attacks 10 years ago.

Domestic revenues tumbled to a 2011 low of about $77 million this weekend, according to studio estimates Sunday.

It's the worst weekend in more than three years, since the weekend after Labor Day in 2008, when revenues amounted to $67.6 million, according to box-office tracker Hollywood.com. And it comes after an $81 million total a week earlier that had been this year's previous low.

Divided by this year's average ticket price of $7.96, the combined $158 million haul means only an estimated 19.8 million people went to the movies the past two weekends. Based on the average ticket price, this year's top-grossing film, Harry Potter and the Deathly Hallows: Part 2, drew more people all by itself over opening weekend.

The two lowest-grossing back-to-back weekends of the past decade came amid the nation's shock after the 2001 terrorist attacks, when one of the last things on people's minds was catching a film. Revenues those two weekends totaled just $126 million; divided by 2001's average ticket price of $5.65, that means 22.3 million people went to the movies those weekends right after Sept. 11 -- 2.5 million more than over the past two weekends.

A couple of bad weekends don't make a trend, yet domestic revenues have been lagging throughout 2011, a year in which many studio executives expected to do record business. Revenues this year are at $9.57 billion, about 4 percent below last year's, according to Hollywood.com.

Revenues this past weekend are down 17 percent compared to the same period last year, when business totaled $91.8 million, led by a $24 million debut for The Chronicles of Narnia: The Voyage of the Dawn Treader.

The slowdown the past two weeks followed a quiet Thanksgiving weekend, when new movies failed to pack in the projected droves.

Next weekend begins Hollywood's end-of-year blockbuster frenzy, with the debuts of Robert Downey Jr.'s Sherlock Holmes: A Game of Shadows and the family sequel Alvin and the Chipmunks: Chipwrecked.

Charlize Theron's comic drama Young Adult goes wide after starting in limited release this past weekend, while Tom Cruise's Mission: Impossible -- Ghost Protocol launches in huge-screen IMAX theaters before expanding to general release the following week.