Iran, China, India, Brazil, and South Africa were the only developing countries among the 31 nations that produced 97.5% of the most cited scientific articles in a study published in 2004. The remaining 162 countries contributed less than 2.5%. The Royal Society in a 2011 report stated that in share of English scientific research papers the United States was first followed by China, the UK, Germany, Japan, France, and Canada. The report predicted that China would overtake the United States sometime before 2020, possibly as early as 2013. China's scientific impact, as measured by other scientists citing the published papers the next year, is smaller although also increasing.