Apple spent $6 billion in 2014 on research and development, nearly double its 2012 R&D budget of $3.4 billion, according to the annual report released Tuesday. No doubt a big part of that cost was connected to Apple Watch, its first all-new product in several years, expected to be released in early 2015.

But don't assume Apple Watch accounted for the majority of that spending. “There are products we’re working on that no one knows about, yes -- that haven’t been rumored about yet,” Apple CEO Tim Cook said in an interview last month.

The bulk of Apple's R&D spending went to increased staffing and benefits. Though research and development cost for Apple has continued to grow, it still remains at just 3 percent of the company’s net sales, which grew to $182.8 billion in 2014, a 7 percent increase from last year’s sales of $170.9 billion.

Company acquisitions have also been a major expense for Apple this year at $3.8 billion, $3 billion of which was used to acquire Beats Electronics and Beats Music.

The increased expenses come as Apple acknowledged iTunes music sales have declined:

“Growth in net sales from the iTunes Store was driven by increases in revenue from app sales reflecting continued growth in the installed base of iOS devices and the expanded offerings of iOS Apps and related in-App purchases. This was partially offset by a decline in sales of digital music.”