obsid   target                  start time      int time    inst    ccd     grat    drop rate(%)
-----------------------------------------------------------------------------------------------------------
6068	Cas_A[S3,-120,-     	102:32928.722		 2.1	ACIS-S	I6		NONE	6.8
6082	Cas_A[S3,-120,-     	296:21098.345		 2.1	ACIS-S	I6		NONE	7.1