The Hybrid Scorecard was created by the Union of Concerned Scientists (UCS) to give consumers a comprehensive comparison of hybrid electric vehicles available in the U.S. market. The UCS Hybrid Scorecard ratings take into considerations fuel economy as rated by the U.S. Environmental Protection Agency (EPA); the environmental benefits as compared to its similar or closest conventional internal combustion engine counterpart; how cost-effectively a particular hybrid achieves its environmental performance; and premium features that are bundled on a hybrid as standard equipment raising its purchase price. The Hybrid Scorecard is available to the public through the Hybridcenter.org website, created in 2005 by the Union of Concerned Scientists to provide consumer and technology information about hybrid vehicles. The first scorecard was published in January 2010, for 2009–10 model year hybrids. The 2011 Hybrid Scorecard was published in July 2011, and evaluated 34 hybrids from the 2011–12 model years available in the U.S. The scorecard was retired in 2013 and was replaced in 2015 with an online tool that calculates electric vehicle emissions. Variables All hybrid vehicles are grouped into two broad categories, non-luxury and luxury models, and the Hybrid Scorecard score for each hybrid electric vehicle available in the U.S. market is assessed considering the following four variables: combined miles per gallon, environmental improvement score, hybrid value, and forced features. Combined miles per gallon This category considers the combined fuel economy rating for highway/city as estimated by the U.S. EPA and expressed in miles per gallon. Environmental Improvement Score This category measures the smog-forming and global warming pollution performance of a hybrid against its similar or closest conventional gasoline counterpart, and thus, it does not reflect the vehicle's overall greenhouse gas emissions performance relative to the average vehicle. Global warming emissions reduction The greenhouse gas emission reductions are calculated as a percent reduction based on the combined city/highway fuel economy ratings for both the hybrid and non-hybrid model according to the ratings published in EPA's fuel economy guide available online at www.fueleconomy.gov. The score is measured in a scale from 0 to 10, where 10 is the best rating. The scores are assigned in relative terms, then a 10 is assigned to the hybrid with the largest reduction in greenhouse gas emissions, while a zero is assigned to the hybrid with the smallest reduction. The values assigned to the models are calculated through linear interpolation between the two end points. For