7910191
 7920191
 7930191
 7940191
 7950191          Instrument out of operation
 7910291
 7920291
 7930291
 7940291
 7950291          1992 Coefficients in use
 7910391
 7920391
 7930391
 7940391
 7950391          1992 Coefficients in use
 7910491
 7920491
 7930491
 7940491
 7950491          1992 Coefficients in use
 7910591
 7920591
 7930591
 7940591
 7950591          1992 Coefficients in use
 7910691
 7920691
 7930691
 7940691
 7950691          1992 Coefficients in use
 7910791
 7920791
 7930791
 7940791
 7950791          1992 Coefficients in use
 7910891
 7920891
 7930891
 7940891
 7950891          1992 Coefficients in use
 7910991
 7920991
 7930991
 7940991
 7950991          1992 Coefficients in use
 7911091
 7921091
 7931091
 7941091
 7951091          1992 Coefficients in use
 7911191
 7921191
 7931191
 7941191
 7951191          1992 Coefficients in use
 7911291
 7921291
 7931291
 7941291
 7951291          1992 Coefficients in use