MAX START DATE: 
Jan 1967 
       
MIN END DATE: 
Dec 2016 
       
BAD SERIES: 
1) HWI -- ends before minimum allowable end date 
2) HWIURATIO -- ends before minimum allowable end date 
3) ACOGNO -- starts after maximum allowable start date 
4) ANDENOx -- starts after maximum allowable start date 
5) NONBORRES -- series switches to negative 
6) TWEXMMTH -- starts after maximum allowable start date 
7) UMCSENTx -- missing at least one observation 
