7910190
 7920190
 7930190
 7940190
 7950190          Instrument out of operation.
 7910290
 7920290
 7930290
 7940290
 7950290          1992 Coefficients in use
 7910390
 7920390
 7930390
 7940390
 7950390          1992 Coefficients in use
 7910490
 7920490
 7930490
 7940490
 7950490          1992 Coefficients in use
 7910590
 7920590
 7930590
 7940590
 7950590          1992 Coefficients in use
 7910690
 7920690
 7930690
 7940690
 7950690          1992 Coefficients in use
 7910790
 7920790
 7930790
 7940790
 7950790          1992 Coefficients in use
 7910890
 7920890
 7930890
 7940890
 7950890          1992 Coefficients in use
 7910990
 7920990
 7930990
 7940990
 7950990          1992 Coefficients in use
 7911090
 7921090
 7931090
 7941090
 7951090          1992 Coefficients in use
 7911190
 7921190
 7931190
 7941190
 7951190          1992 Coefficients in use
 7911290
 7921290
 7931290
 7941290
 7951290          1992 Coefficients in use