  Religious adherence can be considered as a degree of freedom, in a
statistical physics sense, for a human agent belonging to a population. The
distribution, performance and life time of religions can thus be studied having
in mind heterogeneous interacting agent modeling in mind. We present a
comprehensive analysis of 58 so called religion (to be better defined in the
main text) evolutions, as measured through their number of adherents between
1900 and 2000, - data taken from the World Christian Encyclopedia: 40 are
considered to be ''presently growing'' cases, including 11 turn overs in the XX
century; 18 are ''presently decaying'', among which 12 are found to have had a
recent maximum, in the XIX or the XX century. The Avrami-Kolmogorov
differential equation which usually describes solid state transformations, like
crystal growth, is used in each case in order to obtain the preferential
attachment parameter introduced previously. It is often found close to unity,
indicating a smooth evolution. However large values suggest the occurrence of
extreme cases which we conjecture are controlled by so called external fields.
A few cases indicate the likeliness of a detachment process. We discuss
different growing and decaying religions, and illustrate various fits. Some
cases seem to indicate the lack of reliability of the data. Others, departure
from Avrami law. We point out two difficulties in the analysis : (i) the
''precise'' original time of apparition of a religion, (ii) the time of its
maximum, both informations being necessary for integrating reliably any
evolution equation. Moreover the Avrami evolution equation might be surely
improved, in particular, and somewhat obviously, for the decaying religion
cases.
