version 2
Source: IERS Bulletin A (2000_2000_2)

Orbits: to be used with the IGS Rapid Service Orbits (IGR)

  MJD      Xpole   Ypole  UT1-UTC    LOD  Xsig  Ysig   UTsig  LODsig  Nr Nf Nt
             (10**-6")       (0.1 usec)    (10**-6")    (0.1 usec)  
51679.50   90433  329399  2276109  11913   144    87      79       0   0  0  0
51680.50   90993  329150  2264878  10548  2176  2146    1536       0   0  0  0
51681.50   91492  328812  2255204   8800  4650  4650    4024       0   0  0  0