Company TimePeriod IndividualID Date.Indiv.Acted  Value
1  1         2015          A           2015-01-01    400
2  1         2015          B           2015-02-01    400
3  1         2015          A           2015-06-15    400
4  1         2015          C           2015-07-12    400
5  1         2016          A           2016-07-15    400
6  1         2016          B           2016-08-09    100
7  1         2016          C           2016-09-10    100
8  1         2016          A           2016-10-11    600
9  2         2004          A           2004-07-12    200
10 2         2004          B           2004-08-12    300

Company TimePeriod IndividualID Date.Indiv.Acted  Value CumMean
1  1         2015          A           2015-01-01    400   400
2  1         2015          B           2015-02-01    200   300 (row 1 and 2)
3  1         2015          A           2015-06-15    400   300 (row 2 and 3)
4  1         2015          C           2015-07-12    300   300 (2,3,4)
5  1         2016          A           2016-07-15    400   400 (5)
6  1         2016          B           2016-08-09    100   250 (5,6)
7  1         2016          C           2016-09-10    400   300 (5,6,7)
8  1         2016          A           2016-10-11    100   200 (6,7,8)
9  2         2004          A           2004-07-12    200   200 (9)
10 2         2004          B           2004-08-12    300   250 (9,10)