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)  
51635.50   75591  345859  2760561   8331    57    29     147       0   0  0  0
51636.50   76140  345869  2751471   9848  2124  2115    1575       0   0  0  0
51637.50   76660  345826  2741001  11092  4650  4650    4024       0   0  0  0