Research and development yields product and process innovations, adds to the knowledge base of industry, and is a key driver of economic growth. On average, business performs 74 percent of all U.S. R&D. After steadily rising in the 1980s and falling in the early 1990s, industry R&D as a share of GDP climbed to a peak in 2000 at nearly 2.03 percent of GDP, and then declined through 2004. In 2009, industry R&D was only slightly lower, at 2.02 percent of GDP. Delaware far surpasses other states in R&D as a share of worker earnings in part because its R&D performance is dominated by a few firms-such as DuPont-with extremely high R&D investment.