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)  
51630.50   73038  348355  2786862   4039    58    89     136       0   0  0  0
51631.50   72818  347679  2782894   3896  2124  2144    1564       0   0  0  0
51632.50   72693  347066  2778671   4550  4650  4650    4024       0   0  0  0