Well, for one thing, the first number in that line does not conform to your $fl definition (numbers, dot, numbers), because it is "digit, comma, blank, digit digit digit".

Another thing: Why are you assigning with \$levene = \$4? You're taking a reference to the fourth match? I find that deeply suspect, and likely to be a cause of all sorts of funny trouble. (Were you perhaps a C programmer in a previous life? Because that smells of the C idiom that is not needed in Perl). Try losing those backslashes (unless you really, really know what they're there for).