We are not the target audience for them, primary school age kids are, all the local schools have been given 50% off vouchers for entry and hotel stay for kids to take home and badger their parents to use, and nearly all have trips planned for between now and end of the School year.
The Secondary Schools have a similar deal with Thorpe Park, and all the Infant schools have the same deal with Legoland, most primary schools have deals with both, my son has had trips to Legoland and Chessie in the last 3 years, funny though he went to Thorpe first when asked by us where he wanted to go, since Lego and Chessie were boring.
That's what you call a captive audience, and that's why entry has increased, there has been a steady increase of children born in Surrey for the last 10 years, and it's not expected to decrease anytime soon.
Oh and believe me, a 8-10 year old can be very persuading, especially when the only alternative is to let the kids play minecraft all day since there's nothing else to do round here that's affordable (believe it or not, the vast majority of people living within Chessie's catchment area, are not well off).