obsid   target                  start time  int time        inst    ccd     grat    drop rate(%)
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764	SN1999em            	317:61849.913	29.2		ACIS-S	I5	NONE	10.2
324	NGC_4636            	339:01611.326	9.8		ACIS-I	I5	NONE	11.1
1508	SI_Safing_Test_     	349:48229.066	13.4		ACIS-S	I5	HETG	18.6
840	PKS_0548-322        	365:06621.542	5.2		ACIS-I	I5	NONE	9.1