irr.py output

file std_notax.csv:
   NPV at 5% = $1015.5M, IRR = 17.9%

file std_tax.csv:
   NPV at 5% = $175.7M, IRR = 9.1%

file std_ev.csv:
   NPV at 5% = $595.6M, IRR = 14.5%

file ccs.csv:
   NPV at 5% = $536.5M, IRR = 11.6%