hello,

i have a ranking of certain elements and the time associated with each.

set rank time
row 1 cat 1 1.5
row 2 dog 3 4
row 3 cat 3 7
row 4 cat 2 3
row 5 dog 1 1
row 6 cat 4 0 .5
row 7 dog 2 3

i want a column that returns the accumulated time already spent on that
element.

eg.
cell D4 would eaual 1.5
cell D5 would equal 0

any help really appreciated.