sentences:  Over a 1-year period (from March 2001 to February 2002) in total 3,864 responses were received.During the corresponding period some 8,578 actual downloads of the software were independently logged via the same route at the AIDA Website, giving a response rate for this survey of 45%.Responses were received from participants in 66 countries — over half of these (n=2,137; 55.3%) were from the United States and the United Kingdom.