Enthalpy of Reaction

Chlorination of methane involves two kinds of steps:
one initiation step and two propagation steps.
but while calculating the enthalpy of the whole chlorination of methane , only the enthalpies of two propagation steps are added
initiation step:

Br_{2} \rightarrow 2Br^{\bullet } \Delta H = +192kJ

propagation steps:

CH_{4} + Br^{\bullet }\rightarrow HBr + CH_{3} ^{ \bullet } \Delta H = +67KJ

CH_{3}^{\bullet } + Br_{2}\rightarrow CH_{3}Br + Br^{\bullet } \Delta H = -101KJ

in any book the total enthalpy of the reaction is given equal to
-34KJ i.e. [+67 + (-101) ]KJ
why the enthalpy of initiation step not added in the total enthalpy????
plzz explain