TABLE_NAME|COLUMN_NAME|DATA_TYPE|DATA_LENGTH|FIELD_DESCRIPTION QRTLY EMPLOY/PROD|MINE_ID|VARCHAR2|7|Identification number assigned to the operation by MSHA. Use mine_id to join to the Mines table. QRTLY EMPLOY/PROD|MINE_NAME|VARCHAR2|50|Current mine name. QRTLY EMPLOY/PROD|STATE|VARCHAR2|2|State in which the mine is located that is reporting employment and production. QRTLY EMPLOY/PROD|SUBUNIT_CD|VARCHAR2|2|Code that identifies the location within a mine. QRTLY EMPLOY/PROD|SUBUNIT|VARCHAR2|32|Description of the subunit code referring to a location within a mine: (01) Underground operation; (02) Surface operation at underground mine; (03) Strip, quarry or open pit; (04) Auger (Coal only); (05) Culm bank or refuse pile (Coal only); (06) Dredge; (12) Other surface (Metal/Non-Metal only); (17) Independent shop or yard; (30) Mill operation/preparation plant; (99) Office workers at mine site. QRTLY EMPLOY/PROD|CAL_YR|NUMBER|4|The 4-digit year of the employment/production data. QRTLY EMPLOY/PROD|CAL_QTR|NUMBER|1|The single-digit quarter for which the employment and coal production is reported. QRTLY EMPLOY/PROD|FISCAL_YR|NUMBER|4|The four-digit fiscal year of the employment/production data. MSHA's fiscal year begins October 1 and ends September 30. QRTLY EMPLOY/PROD|FISCAL_QTR|NUMBER|1|The single-digit fiscal quarter for which the employment and production data is reported. QRTLY EMPLOY/PROD|AVG_EMPLOYEE_CNT|NUMBER|6,2|Average number of employees reported by the operator for the applicable quarter, subunit and year beginning with 2000. Can be zero. QRTLY EMPLOY/PROD|HOURS_WORKED|NUMBER|9|Total employee hours reported by the operator during the quarter for this subunit, year and quarter. Can be zero. QRTLY EMPLOY/PROD|COAL_PRODUCTION|NUMBER|9|Quarterly coal production, in tons, reported by the operator for the applicable subunit. May be zero or null values. QRTLY EMPLOY/PROD|COAL_METAL_IND|VARCHAR2|1|Identifies if the employment and production are being reported for a Coal or Metal/Non-Metal mine.