religious changing global landscape births deaths regional level patterns country pew populations
religious global landscape distribution major groups report 2010 size world
religious global pew landscape muslims changing islam deaths research world growing christians why fastest estimated births shares religiously unaffiliated center
religious religion global decline population landscape world changing people than nones there unaffiliated projected share religiously pew majority deaths asia
global religious landscape changing population birth change religion muslim christian groups islam christianity pew percent world christians muslims rates 2060