Output volume stats as clean ints so they can be more easily used dow…

[philipbelesky]

For my purposes, it would be useful to take the cut/fill figures and use them to make graphs with Human UI and to trigger a 'success' state when the balanced volume is within a certain range. While string substitution is possible in Grasshopper, it's a royal pain so it would be great if the stats output put 'clean' numbers that could be easily plucked using List Item and used downstream. The other slight benefit is that this more easily differentiates the timing logs from the analysis outputs.