Not sure I can agree, as foreign tourists cannot be separated from any other type of fan paying at the gate. An admission fee is the same regardless of who is paying it..
My rationale for mentioning foreign tourists is that I'm quite confident that a higher proportion of them are F1 fans compared to the locals in Miami and Las Vegas. I need to go online and find it again but I think it was the Miami Herald (newspaper) that mentioned that well over 50% of the attendees of the Miami GP were foreign tourists.
