Hi Amanda!
I am the Membership Coordinator at Denver Zoo and have been doing similar research within the zoo realm! I hope this information is helpful:
1. Denver Zoo
2. Our member renewal rate has been around 61% for the past two years.
3. We have about 1.5 million visitors annually.
4. We were expecting to have about 48k households this year; however, we ran a unique offer for "Celebrate Colorado" and gave the steepest discount we have ever offered, which was 50% off. I will also add that this was to help mitigate the on-site experience with construction; nonetheless, we have more households than anticipated due to this offer - we currently have about 51k households and expect more before the end of the year.
I hope this helps! If you have any questions for me, please do not hesitate to reach out π