Coming in March vs April

[Scoutdog]

Is Seaworld noticeably busier in late-March (Spring Break) as opposed to late April?

I guess I don't really know if everyone's Spring Break is in mid-March like ours. We're thinking of coming:

March 28 - April 4,
or
April 18-25

Does anyone have an idea if either of those weeks will be busier than others? Or if airfare is typically higher for either?

Thanks again!