He also accused AIDRG of selective use of data and multiple systematic errors in their analysis, claiming that the authors assumed the Palestinian Electoral registry to be complete even though registration is voluntary, and they used an unrealistically low Total Fertility Ratio (a statistical abstraction of births per woman) to reanalyse that data in a "typical circular mistake." DellaPergola estimated the Palestinian population of the West Bank and Gaza at the end of 2005 as 3.33 million, or 3.57 million if East Jerusalem is included. These figures are only slightly lower than the official Palestinian figures. The Israeli Civil Administration put the number of Palestinians in the West Bank at 2,657,029 as of May 2012.