Which ions has exceptionally higher values ?
The hydrogen ion, because of its small size has high charge density and is heavily hydrated. Thus, we expect the mobility of ion to be low rather than high.
The high mobility of ions is hydroxlytic solvents such as can be explained by Grouttus type meachanism in which a proton moves rapidly from to a hydrogen-bonded water molecule and is transferred along a series of hydrogen bonded water molecules by a rearrangement of hydrogen bonds (just like a relay race).
Amongest negatives ions, has the highest ionic mobility.