Can someone give more details about gas fillings in T5 fluorescent lamps?
I know that the classic 4, 6, 8, 13 W lamps have argon fill, but I'm not sure about others.

There are 11, 15 and 16 W lamps which have the same length as 6and 8 W lamps.
And T5 HE and HO. Is the only diffrence in the electrodes or do they have a different gas filling pressure or even a different gas like krypton?
I know that T8 16, 32 and 51 W 'Eco'(Philips name) or 'ES' (Osram name) have xenon as the buffer gas, so maybe energy saving T5 tubes also have something other than argon. Even T5 HE and HO comes in a more recent energy saving version, like Philips Master TL5 ECO 25, 50, 73 W.