Of the 207 countries listed, the total population (as given) is 4,318,999,818, the total number of JWs is , an average rate of one JW per 707 people.
According to http://www.census.gov/ipc/www/worldpop.html, the world population in 2001was 6,153,995,400
Therefore the 28 countries not listed had a population of 1,834,995,582 with just 9,914 JWs to preach to them, a ration of one JW per 185,091 people.
In total, then, there were 6,117,666 JWs to preach to 6,153,995,400 people, a world ratio of one JW per 1005 people.
(Bear in mind that all the above figures are inaccurate to varying degrees.)