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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def site_occupation_statistics( self ):
 """ Average site occupation for each site type Args: None Returns: (Dict(Str:Float)):
 Dictionary of occupation statistics, e.g.:: { 'A' : 2.5, 'B' : 25.3 } """

        if self.time == 0.0:
            return None
        occupation_stats = { label : 0.0 for label in self.site_labels }
        for site in self.sites:
            occupation_stats[ site.label ] += site.time_occupied
        for label in self.site_labels:
            occupation_stats[ label ] /= self.time
        return occupation_stats