I am working on a scenario that requires a ZR of 93, yet no matter what I can't raise it above 89 or 90. I don't have a problem keeping a high guest happiness, so I'm not sure where the problem lies.
Also, how to you arrange your exhibits/attractions? Do you follow the edge of the zoo or spread out into the middle? Do you make a circle so guests don't have to double-back, or no? I'm curious which techniques are most successful.