State Street utilizes the GHG Protocol Corporate Standard and IPCC AR4 as the GWP sources. The underlying usage used in calculating the emissions is based on actual metered data from the majority of the sites. For those sites without metered data an estimated usage level was derived by taking the actual usage levels of other State Street sites with metered data against a square footage or employee count. This was then applied to the estimated sites by using the square footage or employee count to determine the usage levels. State Street calculated Scope 2 emissions using both the market-based and location-based approaches. The location-based methodology has been used for the reported data.