Delete FTA Results?

I'm trying to get some simple results from my fault tree, however everytime I run it, instead of giving me the results for what I just ran (12 data points when I request 12), it appends the jsut run simulation onto the existing results (adds 12 data points to the existing 1000s, so I end up with x+12). I assume that when I run the FTA, the "removing existing results" function isn't working.

Is there any way to manually delete results?