public function getReportingRateTrendAction()
 {
     $year = $this->_request->getParam('year', '');
     $month = $this->_request->getParam('month', '');
     $province = $this->_request->getParam('province', '');
     $district = $this->_request->getParam('district', '');
     $geoModel = new Model_Geo();
     $return = $geoModel->getReportingRateTrend($year, $month, $district);
     echo Zend_Json::encode($return);
 }