GHG Intensities of Companies

I made this table today for my report.  The total GHG is the combined Scope 1, 2, and 3 for each company.  All of them reported the Scope 1 and 2 for 2013, but I had to estimate the Scope 3 for Exxon Mobil, Target, and TJX.  Which carbon metric should be used?  Well, if we are comparing between companies in the same sector, it doesn't seem to matter.  Exxon Mobil is always worse than Chevron, Target is always worse than TJX, and Google is always better than Microsoft.  So what does this mean?  Well, I'm not exactly sure.  

GHG/revenue (lbs/$)	GHG/marketcap	GHG/enterprise value	GHG/profit
Exxon Mobil	Exxon Mobil	Exxon Mobil	Exxon Mobil
Dow Chemical	Dow Chemical	Chevron	Dow Chemical Company
Chevron	Chevron	Dow Chemical Company	Chevron
Target	Target	Target	Target
Microsoft	TJX Companies Inc.	TJX Companies Inc.	TJX Companies Inc.
TJX Companies	Microsoft	Microsoft	Microsoft
Google	Google	Google	Google