Complex sentence: The membership was increased by 30 in each of the second term (1997--2001), third term (2001--2005) and fourth term (2005--2009) councils, given 150 members plus the speaker in the fourth term council.
Split into simpler sentences: The membership was increased by 30 in each of the following terms: the second term (1997--2001), third term (2001--2005) and fourth term (2005--2009). Thus, the number of members increased to 150 members plus the speaker in the fourth term council.