Complex sentence: The fourth series began in March 2008, the fifth series in March 2009, the sixth series in October 2010, the seventh series in May 2011, the eighth series in March 2012,the ninth series in May 2013, and the tenth series in October 2014.
Split into simpler sentences: The fourth series began in March 2008, and the fifth series in March 2009. These were then followed by the sixth series in October 2010, the seventh series in May 2011, the eighth series in March 2012, the ninth series in May 2013, and the tenth series in October 2014.