Complex sentence: On 17 December 2015, the TTC announced that Presto will be available on 100 of the 230 older streetcars starting that day, with the remainder active by the end of 2015.
Split into simpler sentences: On 17 December 2015, Presto was available on 100 of the 230 older streetcars. It will be available on the remainder by the end of 2015.