Calculate inventory on a given date

I've got a dataset consisting of some items that are continously added to the inventory and continously removed from the inventory. In this way each item has a start date and an end date (if removed) or the end date is empty. An example is given below. I want to create a graph with drill down where you on a given date can see how many items is on the inventory and by drilling down yoy can see the items. Any suggestions about how to accomplish this?

Item     Start_date     End_date

Item1   1/1-2015       30/4-2016

Item2   3/2-2015       2/2-2016

Item3   4/4-2016

Item4   5/1-2015       7/6-2015