The World Intellectual Property Organization (WIPO) oversees the Patent Cooperation Treaty (PCT) scheme where a single patent application can be published which applies to patent offices in numerous countries or regional authorities. Each of those offices then decides whether or not to grant a patent. PCTs are what many refer to as the World patent.
A press release gives statistics on 2009 activity in the PCT. Filed applications were down 4.5% on 2008, and amounted to about 155,900. The recession has obviously had an impact, although it was pointed out that Asia did well. China's share was up a massive 29%, to 6,946, while the USA was down 11%. It was still the leading country, with 45,790 applications.
There were small increases in Japan, Korea, France and The Netherlands among the top 15 countries. Data is also provided on the top companies (Japan's Panasonic was top) and on numbers of applications in many fields of technology. The biggest increases were 10% growth over 2008 in both semiconductors and in nano-technology -- most fields, of course, showed drops in numbers.
What used to be called the trilateral report on statistics for the three major granting patent offices (Europe, Japan, the USA) has, significantly, been extended to Korea as well for 2008 in the four offices statistical report. Data going back to 1996 is available at their site.
The US Patent and Trademark Office has a page with links to their statistics, including data on applicants and on applicants from individual states and metropolitan areas.
Lastly, WIPO has a page linking to national data or annual reports with patent statistics.
[WIPO also has links to statistics on the numbers of patents, trade marks and designs for each country, going back to 1995, with some analysis, at this site. Ed., 13 October 2011]