For the first time in 43 years, the United States leads the world in the filing of new patents, according to a report from the United Nations' World Intellectual Property Organization (WIPO). In 2006, the most recent year for which figures are available, the U.S. Patent and Trademark Office received 426,000 filings, approximately one-quarter of the 1.76 million patents filed worldwide. Of the U.S. patent filings, only about half are from American inventors. However, the WIPO's deputy director-general says there were more than 1 million unprocessed patent applications at the U.S. patent office in 2006 and the increasing activity is causing a backlog that would take more than two years to clear. More than three-quarters of the patents granted in 2006 were concentrated in Japan, South Korea, Germany, and China, along with the United States. Chinese applicants filed 32 percent more patent applications than the previous year, both in China and in other nations.