A survey for Christian countries only:
http://www.religioustolerance.org/rel_comp.htm
Two international surveys were conducted during 1991 and 1993 by the International Social Survey Program (ISSP). This is currently located at the National Opinion Research Center (NORC) at the University of Chicago.
The results on the evolution question may reflect the strength of a scientific, secular world view in the society. The results on the existence of God might reflect the strength of traditional religious belief. The two seem to be inversely related.
http://www.csicop.org/scienceandmedia/evolution/
Polling Opinion about Evolution
The available poll indicators reflect a “low information” public when it comes to the debate over evolution and science education. Few citizens possess both the motivation and the ability to understand the science and politics behind the evolution-creation controversy, and to actively deliberate the merits of proposed policies. Instead, the low information public is likely to rely heavily on their pre-existing views and only the information most readily available to them in the media as the fuzzy material from which to focus their opinions.