At least 75%, and it'll be more in Boston, Wrigley, Meadowlands in NJ- the American crowd is mostly of the "Nice! you wanna go see GnR at Fenway??! That'll be awesome- then this wintah we'll go see th' New Kids at the Gah-den- holy throwback, kid!" variety.
On that note, new releases won't nudge the ticket sales needle in the States (IMO); maybe it would help in South America where the fan base is massive AND more up on the current band, but who knows?