obsid   target                  start time      int time    inst    ccd     grat    drop rate(%)
-----------------------------------------------------------------------------------------------------------
13751	Crab                	12:08784.389		 4.6	ACIS-S	S1		NONE	25.5
13752	Crab                	41:38029.660		 4.6	ACIS-S	S1		NONE	25.6
14416	Crab                	79:23026.623		 4.6	ACIS-S	S1		NONE	25.4
13754	Crab                	113:14040.014		 4.6	ACIS-S	S1		NONE	25.2
13755	Crab                	229:41261.854		 4.6	ACIS-S	S1		NONE	24.6
13756	Crab                	255:77315.811		 4.6	ACIS-S	S1		NONE	24.6
13757	Crab                	289:31672.704		 4.6	ACIS-S	S1		NONE	24.4
14458	Crab_pulsar         	331:77074.717		 9.6	ACIS-S	S1		NONE	25.1