Summary data populated from column entries

Is there a way to automatically populate summary data fields based on the entries in a particular column, rather than having to identify all of the unique values and add summary fields one by one? For example, column 1 contains multiple instances of person 1, person 2, person 3, etc, and column 2 contains numeric values which I want to sum for each different person. The people listed in column 1 will change over time, but I don't want to have to update the summary data fields each time someone new is listed. I realise there's a new feature in reports for grouping data, but I want to create graphs in dashboards relating to this summary data.