 
Format of the 1984 mass table:
code, mass excess (keV), error, symbol, mass excess (AMU), error
as a Fortran format (I8,T13,F9.2,T23,F7.2,T31,A6,F10.3,T51,F8.3)
For Z<100 code=10E5*A+90000+10*Z,
otherwise code=10E5*A+90000+10*(Z-100)
`Systematic' masses are indicated by a negative error on the excess.
