Table 3: Main properties of the dm radio spikes with and without internal structure, shorter than 100 ms, observed between February 2000 and December 2001 with the 15-m radio telescope and fast radiospectrograph of Torun Observatory.

	Spikes without internal structure	Spikes with internal structure
No. spikes	1699	1837
Duration (s)
min/max	0.008/0.099	0.003/0.099
mean/median (skew.)	0.029/0.024 (1.9)	0.046/0.047 (0.1)
Width (MHz):
min/max	3.1/31.4	3.0/25.9
mean/median (skew.)	10.38/9.5 (1.0)	9.2/8.7 (0.9)
Relative width (%)
min/max	0.21/2.24	0.21/1.82
mean/median (skew.)	0.73/0.68 (1.0)	0.65/0.61 (0.9)
Negative drifts (MHz/s)
No. spikes	381	1462
min/max	64/5462	63/12141
mean/median (skew.)	1089/762 (1.7)	467/321 (9.1)
Positive drifts (MHz/s)
No. spikes	236	136
min/max	111/9102	51/13425
mean/median (skew.)	1460/1113 (2.3)	942/604 (6.1)