Not an IFTA member
Hawaii has no IFTA diesel rate
IFTA covers the 48 contiguous states and 10 Canadian provinces. Alaska, Hawaii and the District of Columbia are not members, so no miles are apportioned to Hawaii and no rate is filed against it. A blank here is the correct answer, not missing data.
That does not mean fuel is untaxed in Hawaii. It means the tax is collected at the pump in the ordinary way instead of being reconciled across states on a quarterly return, so what you pay is simply built into the price you paid.