def statistics(filters = {}, except = nil)
      (@statistics || {}).inject({}) do |stats_hash, stat|
        stats_hash[stat.first] = send(stat.last, filters) if stat.last != except
        stats_hash
      end
    end
def statistics(filters = {}, except = nil)
      (@statistics || {}).inject({}) do |stats_hash, stat|
        stats_hash[stat.first] = send(stat.last, filters) if stat.last != except
        stats_hash
      end
    end
Calculates all the statistics defined for this AR class and returns a hash with the values.
 There is an optional parameter that is a hash of all values you want to filter by.

 EXAMPLE:
 MockModel.statistics
 MockModel.statistics(:user_type => 'registered', :user_status => 'active')