Attendance does not mean everything because locations and weather plays a huge rule for Amusement Park attendance.
There is a reason Trip Advisor has Bay Beach Amusement Park ranked number 17 Despite its attendance. Bay Beach Amusement Park is very likely the most affordable Amusement Park in the entire United States that caters to little kids and has been around since 1892. Bay Beach from 1937 to 2010 did not have a roller coaster at all, but its prices kept the Amusement for decades. I went there as a little kid when my family visited Green Bay, Wisconsin when I was a kid. Bay Beach didn't have a roller coaster when I was a kid.
Bay Beach Amusement Park has free parking, Free Admission. and you have the option of bring you own food and eat at a picnic table. The rides currently cost 25 cents, 50 cents, 75 cents, and the amusement parks only roller coaster costs a dollar according to their website. Bay Beach also right now is middle of an expansion due to the city bought 46 more acres of land.
Bay Beach Amusement Park is the new home of Elvis Presley's Roller Coaster called Zippin Pippin. If you live in Wisconsin with little kids, it is more affordable than a Disney theme park is like it or not.
Bay Beach Amusement Park can't match the attendance of many theme parks despite theme having 3.5 million riders last year according to their pr department. Bay Beach Amusement Park is only open every day from June to end of August. Bay Beach Bay Amusement Park is open less than 30 days combined in May and September. The Amusement Park is limited in amount of days due to weather since it runs outdoors and the location due goes get cold and gets snow.
The other thing is this amusement park is located in Green Bay, Wisconsin. Green Bay, Wisconsin is not the tourist spot like Orlando, Florida.