Get a list of the measuers of this datatable
            Measures can be "Antal Besök inom 7 dagar",
            "Måluppfyllelse vårdgarantin", etc

def measures(self):
        """ Get a list of the measuers of this datatable
            Measures can be "Antal Besök inom 7 dagar",
            "Måluppfyllelse vårdgarantin", etc
        """
        if self._measures == None:
            self._measures = get_unique([x["measure"] for x in self.data])

        return self._measures