Table 1: The results of the Kolmogorov-Smirnov tests for the three subclasses. The first column denotes the subclass; the second the number of GRBs of this subclass; the third column gives the difference D between the theoretical and empirical cumulative function; the fourth column gives the significance (in percentage) of the rejection of the null-hypothesis of isotropy (Eq. (14.3.9) of Press et al. 1992).

subgroup	N	D	%
short	497	0.049	82.1
intermediate	301	0.054	76.5
long	1239	0.046	99.0
non-short	1540	0.021	51.2
all	2702	0.021	77.2