Complex sentence: Commercially bottled kombucha became available in the late 1990s and by 2014 US sales were $400 million; $350 million of that was earned by Millennium Products, Inc. which sells "GT's Kombucha".
Split into simpler sentences: Commercially bottled kombucha became available in the late 1990s. By 2014 US sales of bottled kombucha were $400 million; $350 million of that was earned by Millennium Products, Inc. which sells "GT's Kombucha".