iCharge Transfer Efficiency is a measure of the percentage of
electrons which are lost at each packet switching location.  A
1000x1000 CCD would undergo 2000 such transfers upon readout.
AT 98% CTE almost all the charge would be lost by the 2000th
transfer.  Consider a packet that contains 100,000 electrons,
after 10 transfers there would be 18% packet loss and after
35 transfers there would be only 50% of the remaining charge
and you still have another 1965 transfers to go!