Complex sentence: By March 2010,84 of DART's 115 LRVs had been converted into SLRVs, and by August 2014, DART was operating a total of 163 SLRVs: all 115 converted LRVs in addition to 48 new units.
Split into simpler sentences: By March 2010,84 of DART's 115 LRVs had been converted into SLRVs. By August 2014, DART was operating a total of 163 SLRVs, consisting of all 115 converted LRVs in addition to 48 new units.