Each system in Table 2 comprises five or six equations corresponding to the
religiosity survey data. The first equation is for data around 1981 from the
World Values
Survey
(WVS), the second is for data around 1990 from WVS, the third is for data around 1991 from the International Social Survey Programme(ISSP), the fourth is for data around 1995 from WVS
, the fifth is for data around 1998 from ISSP, and the last is for 1999 data from Gallup (which lacks data for belief in heaven and hell).