Mean and median investment fund size comparison in the United Kingdom (UK) 2004-2014

Mean (or arithmetic mean) is an average, computed by adding the values and dividing by the number of values. In contrast, the median is the number separating the higher from the lower half of a distribution.
The source adds the following information: "This survey captures asset management undertaken by members of the investment association on behalf of domestic and overseas clients. It is based on the results of questionnaire responses from 72 Investment Management Association member firms, who between them manage 84 percent of total UK assets under management by the entire IMA membership base. The asset value is stated as of December 2014."