it all depends on your 1st year. If people are coming and leaving saying "They blew" or "What a rip off" then your 2nd year will probably be lower as the new factor wore off in addition to disappointment. However if your haunt was good, people are gonna certainly gonna come back and bring their friends. Helps too if you change some of it every year too.
I'm planning to have my 1st year next year and visited most of the haunts in my state an saw they are mostly face paint, jumping out and banging walls. My style is going to be much different and hence a different vibe/experience all together.