Complex sentence: It handled 17.6 billion dollars in transactions in 2016 and 6.8 billion dollars in transactions in Q1 of 2017 which more than doubled its volume in Q1 of 2016.
Split into simpler sentences: It handled 17.6 billion dollars in transactions in 2016. In Q1 of 2017, it handled 6.8 billion dollars in transactions, which more than doubled its volume in Q1 of 2016.