[2008] Loop Calculation - Showing The Break-even Year

I am trying to write the following application. A project has initial investment, yearly revenue and yearly expenses. The program should be able to take these data and calculate the break-even year, i.e. when the cumulative profits become 0. Also, it should have a listbox that would list the cumulative profit for 10 years. Refer to the example below. Now I know how to show it in the listbox but I am having trouble showing the break-even year. I know how to calculate it but how do you show it in years.