Table 2: Summary of the usable exposure durations obtained for the different clusters after accounting for the GTI filtering, telemetry losses etc. In some observations data from only one camera was available. For operational reasons the PN camera commences exposures somewhat later than the MOS cameras. Losses due to proton flares, telemetry drops etc. are given in Col. 4 as a percentage of the total exposure time.

Cluster ID	MOS	PN	% lost
RX J0337.7-2522	23 421	23 611	60
RX J0505.3-2849	31 851	24 983	35
RX J0847.2+3449	43 793	-	50
RX J1120.1+4318	18 333	16 208	18
RX J1325.5-3826	-	48 753	20
RX J1334.3+5030	40 713	34 909	15
RX J1354.2-0222	9090	7248	73
RX J1701.3+6414	9379	4382	50