It really depends on how you define white. What is Caucasian? There is such a wide diversity of races in the world to answer this would be complicated.India, China , Latin America the answer is pretty complex.
Here are some statistics on the US:
In July 2006, 40.2 million people in the United States, or 13.4 percent of the civilian noninstitutionalized population, were Black. They are the second largest minority population, following the Hispanic/Latino population. In 2004, the majority of Blacks lived in the South (54 percent). In comparison, 67 percent (198.3 million) of the United States population was non-Hispanic White: 34 percent lived in the South. The ten states with the largest Black population in 2006 were New York, Florida, Texas, Georgia, California, Illinois, North Carolina, Maryland, Virginia, Michigan. Louisiana is no longer in the top 10, as a result of the Hurricane Katrina disaster. Combined, these 10 states represented 49% of the total Black population. Of the ten largest places in the United States with 100,000 or more population, Detroit had the largest proportion of Blacks, 83%, followed by Philadelphia (44%), and Chicago (38%).
Source:
http://www.omhrc.gov/templates/browse.aspx?lvl=2&lvlID=51