i've took time to actually look up various manufacturers' datasheets and it's: range 50-99%, 95%, 97%, range 95-100%, 99%, unspecified or just data for pure helium. at this point i'm pretty sure there's no such thing as "balloon gas manufacturer", everyone buys 4N+ cryogenic helium and balloon gas consists of odds and ends that come from flushing piping and empty bottles with better stuff