Now I can't say the world may never know...  85 drops may not seem like much, but being you only use around 1-2 drops at a time, that isn't too shabby for a 5 ml bottle.  I'm referencing the 5 ml bottle as those are the size in the premium starter kit.  Most of them when you buy them again are the 15 ml size (some are the 5 ml size still).