The Center on Nonprofits and Philanthropy at the Urban Institute and the Association of Fundraising Professionals established the Fundraising Effectiveness Project (FEP) to conduct research on fundraising effectiveness and help nonprofit organizations increase their fundraising results. The 2011 FEP Donor Retention Supplement are based on data provided by 2,377 participating nonprofits about the 2010 behavior of 1.8 million 2009 donors to their organizations. Donor confidentiality is maintained for all FEP annual surveys. FEP measures and publishes statistics on gains, losses and net growth for both "number of donors" and "amount of gifts" (dollars).