Background: According to China daily. Fifteen years after the satellite system was launched, it is now generating $31.5 billion for major companies such as China Aerospace Science and Industry Corp, AutoNavi Holdings Ltd, and China North Industries Group Corp.
Question: How much revenue for companies is generated by the BDS system?
Answer:<extra_id_0>.
<extra_id_0> $31.5 billion<extra_id_1>