There may be fewer hit albums today than a few years ago, but the titles that do succeed are taking a bigger share of the pie this year.

In the first half of 2010, according to a Billboard analysis of Nielsen SoundScan data, albums that sold more than 1 million units grabbed the biggest share of total sales since 2006. The five titles that surpassed one million units in H1 2010 took 4.7% of all album sales. Only three titles broke one million units in 2008 and four did it in 2009. Million-sellers accounted for 3.7% of sales in 2007, 1.8% in 2008 and 2.7% in 2009. In other words, the most popular titles are faring very well as total album sales continue to crumble.

Similar trends are seen in the market shares of the Top 10 and Top 50 titles. After bottoming out in H1 2008, the market shares of Top 10 and Top 50 titles have rebounded in the last two years and now exceed (Top 10) or match (Top 50) their market shares in H1 2005.

It’s a different story for albums that sold between 500,000 and one million units. In H1 2010 these mid-level hits improved upon the share achieved in H1 2009 but did worse than in previous years. Overall, however, the group’s 7.9% share of total sales is comparable to the 8.4% achieved in 2008 but far worse than 2005 (12.4%), 2006 (11.8%) and 2007 (9.6%).

But, as we all know, each year there are fewer titles reaching the upper stratosphere of album sales. Just five titles reached one million units in H1 2010. While that was more than in H1 2008 and H1 2009, it was far lower than H1 2005 (17) and H1 2006 (16). And only 18 titles sold between 500,000 and one million units in H1 2010. The number has fallen each year from 54 titles that passed the 500,000 mark in 2005.

But once a title reaches 500,000 or one million units, it does about as well as it would have in previous three years. The average for million-plus titles rose in H1 2010 to 1.43 million after falling to 1.17 million in H1 2009, 1.2 million in H1 2008 and 1.42 million in H1 2007.