Complex sentence: First shown on 18 May 2003, five series in total were broadcast with the fifth series and later found to be final series--comprising six 60-minute episodes--debuting on 7 September 2008.
Split into simpler sentences: First shown on 18 May 2003, five series in total were broadcast. The fifth series--comprising six 60-minute episodes--debuted on 7 September 2008.