checkHttpStatus         private function for check the http status
dataJson2df             private function to convert the returned jason
                        data to a dataframe
genDfwds                private function for constructing the query
                        parameter for dfwds
milSec                  private function for sec
statscnDbs              the available dbs
statscnQueryData        query data in the statscn db
statscnQueryLastN       fetch the lastN data
statscnQueryZb          the data categories
statscnRegions          the regions in db
statscnRowNamePrefix    statscnRowNamePrefix
