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).