Countif Formula between Values from a Data Table

Hi,

In short I am trying to count values coming out from a data table, so that I can break the results down into approximate percentages.

Basically in H6 to H10005 I have predicted margin of victory.

Those margins of victory don't vary between +40 and -40 (e.g. an extreme result for one side or the other);

In cells C11 to C91 I have listed the margins -40 through to +40 (with C11 being -40).

To break the margins of victory down (e.g. for -40) I am looking to count the number of times a score between -40.5 and -39.5 occurs.

To do this in D11 I have gone for the following formula - but I have obviously made an error somewhere (as when copied through I am not getting anything counted from the 10000 results):

=COUNTIF($H$6:$H$10005,"(>=(C11-0.5))"-COUNTIF($H$6:$H$10005,"(<=(C11+0.5))"))

I'm struggling to see where I went wrong as the range is good and I thought the criteria was okay (e.g. if C11 is greater than or equal to -40.5 minus if C11 is less than or equal to -39.5). I'm sure I've got something basic the wrong way round so if anyone has any advice I'd be grateful.

Thanks in advance,