with that, i want to bring up the director of the department, melanie nutter. >> good morning. i am so pleased to be here today to celebrate this environmental milestone. as you have heard, we would not be here today without the broad coalition of support and the ongoing collaboration that came together around ensuring we could reduce carbon emissions from our taxi fleet coming here in san francisco. the san francisco department of the environment is proud to have been a partner in insuring san francisco's taxi fleet is the greenest in the nation. first, on the policy front, in 2007, 2008, our department staff work with the taxi commission and cab companies to create the green tax ordinance. this collaboration resulted in a performance standard, requiring taxi companies achieve over all the emission reductions each year without mandating specific models. as long as each company's fleet met the required performance standard at an average level of greenhouse gas reductions every year, they could choose the mix of vehicles that best suits them. secondarily, regarding education, we