6? lol thats not much. At 17, for a guy it would be something to be proud about. For a girl it seemed to be the average[atleast out of the girls i knew well enough who would tell the truth, they told everyone else 2 lol] If you are wondering if shes a slut, then no.
At 19 Taylor Rain had sucked off well over 500 guys now thats a slut! now shes in her mid 20's and that number would be several thousand.
For a normal adult, theres no real formula for whats a high or low number. Considering being in your early 20's i would say an acceptable number would be about 20-30. Over 30 and shes a slut, over 50 and shes a veteran. girls who hold down long term relationships, like 5 years have alot lower numbers then girls who only have medium relationships like a couple of months[and yet most people would be sexing after a few months, so it adds one to the number]
Basically all this shit is too complicated and in most cases you shouldnt ask. This rule doesnt apply to me though unless i really seriously care about them. Usually if its a big number i laugh about it with her, if not then i try and get some of the funny stories. If you think that the number really matters, then you arent mature enough to hear it, and if she thinks that it matters to you, shes only going to lie anyways. its only a number so try not to ask, but if you find out anyways then who cares.