  We analyze the evolution of HII regions around the seven known SDSS quasars
at z>6. The comparison between observed and model radii of the HII regions
generated by these quasars individually, suggests that the surrounding
intergalactic hydrogen is significantly neutral. When all constraints are
combined, the existing quasar sample implies a volume averaged neutral fraction
that is larger than 10% at z>6. This limited sample permits a preliminary
analysis of the correlations between the quasar parameters, the sizes of their
HII regions, and the associated constraints on the neutral hydrogen fraction.
We find no evidence in these correlations to contradict the interpretation that
the red side of the Gunn-Peterson trough corresponds to the boundary between an
HII region and a partially neutral IGM.
