How many topcited papers are there from various countries?
These tables rank individual countries by the number of topcite papers in the SPIRES-HEP database. This is done by looking at where the paper was written rather than the nationality of the author. Thus if a Brazilian physicist, say, writes a topcited paper at CERN it will be counted as a Swiss topcite. If she then moves to Waterloo U., her next paper will count as a Canadian topcite. In addition to this, one paper can count towards the topcite tally of several countries.(Note) Another point to note is that the country is determined by the location of the institution at present (thus, for example, the Soviet Union is not represented, even though many of the Russian topcites date from the USSR era).
In addtion to the above, the usual disclaimer about citations applies. The list is intended for entertainment purposes only, and topcited authors should be modest in their dreams for commercial endorsements. You might also be interested in comparing it with the Real Olympics. Note that we appear to consider physics a summer, rather than winter event. We leave the reader to speculate on the reasoning behind this choice. The national statistics were taken from the CIA World Factbook and might provide interesting context for the numbers (mistakes are probably ours, not theirs).
Footnote:In the 2000 edition, to ensure that a substantial contribution was made by each nation on the paper, the list generally excluded the large multi-national collaborations. The cost of this was a certain bias towards theoretical papers. In the 2004 edition, in the Olympic tradition, we changed the rules. Now we are allowing the experimentalists to compete as well as the theorists, perhaps this is similar to allowing the professional atheletes in the games, or perhaps not. The only papers excluded from the counts are those by the Particle Data Group, whose mastery of citation events is well established.