Table 5: Measured data at SPGF1.

Series name Record date and time L B M x_spgf1_1996(t) 0:00, 1 Jan.–23:00, 15 Dec. 1996 8616 256 33 x_spg1_1997(t) 0:00, 6 Mar.–23:00, 15 Dec. 1997 7080 256 27 x_spg1_1998(t) 0:00, 1 Jan.–23:00, 7 Jan. 1998 168 32 5