In an essay on Sephardi Jewry, Daniel Elazar at the Jerusalem Center for Public Affairs summarized the demographic history of Ashkenazi Jews in the last thousand years, noting that at the end of the 11th century, 97% of world Jewry was Sephardic and 3% Ashkenazi; by the end of XVI century, the: 'Treaty on the redemption of captives', by Gracian of the God's Mother, Mercy Priest, who was imprisoned by Turks, cites a Tunisian Hebrew, made captive when arriving to Gaeta, who aided others with money, named: 'Simon Escanasi', in the mid-17th century, "Sephardim still outnumbered Ashkenazim three to two", but by the end of the 18th century, "Ashkenazim outnumbered Sephardim three to two, the result of improved living conditions in Christian Europe versus the Ottoman Muslim world. According to Daniel Elazar at the Jerusalem Center for Public Affairs, at the end of the 11th century, what percentage of the world's Jewry was Sephardic