Content-related toy sales among top reasons for 6.7 percent growth last year.

U.S. toy sales increased by 6.7 percent and generated $19.4 billion in 2015, marking one of the strongest performances the industry has seen in years, according to the NPD Group.

“The toy industry had an incredible year and, as is typically the case, there isn’t one reason; there were a number of factors coming together to grow the industry nearly 7 percent in 2015,” says Juli Lennett, U.S. toys industry analyst, the NPD Group.

One of the key drivers behind the industry’s growth was content. Whether it was a movie (Star Wars, Jurassic World, Minions and Avengers), TV show, app or strong YouTube following (Shopkins), these properties were top contributors to industry growth. The movies category outperformed the market in 2015, growing by 9.4 percent, due to the early release of Star Wars toys, which managed to become the No. 1 property for the year with more than $700 million in sales.

Additionally, consumers had one extra day to shop this season due to Christmas falling on a Friday. As a result, the week of Christmas grew 25 percent in 2015. Traditionally, the week of Christmas represents 8 percent of all toy sales for the year while the week before Christmas represents 8.5 percent of all toy sales.

Within the toy industry, nine of the 11 super-categories posted gains in 2015. Games/puzzles grew 10.8 percent, vehicles grew 9.7 percent, while other categories such as building sets, outdoor and sports toys, dolls and infant/toddler/preschool toys all posted considerable gains.

NPD also announced the 10 top-selling toys for the year with the Shopkins 12-pack assortment from Moose Toys leading the pack.

“What was especially interesting to see this year among the top 10 selling items was the wide diversity of toys from simple to complex,” says Lennett. “In addition, among the top toys were evergreen properties like Hot Wheels, Barbie, Star Wars, and 'Ninja Turtles' as well as relatively new properties like Shopkins, 'Paw Patrol,' and 'Minecraft.' Price points were also wide ranging, from under $1 to more than $150.”