16th & 17th would be the least crowded, maybe 20th too, followed by 18th, and finally19th. I would expect at least 12,500 Friday and Saturday since it is St. Patricks weekend. I expect 5,000 to 7,500 Wednesday and Thursday since they are weekdays in March. Very few people will be there, even though it will be spring break because most parents will probably have to work and the earlier in the year it is, the less people will be there. But if there is a chance of cold weather, rain, or the sun rarely showing itself, the less people will come.