Hello Mike,
As with the 85%, the 7% nose weight is only a guideline, and as it was established many years ago, it does not necessarily represent a practical figure for modern outfits. 7% falls outside of the legally available range for the outfit.
The law requires that the nose weight must be a minimum of 25Kg and must not exceeded either of the lower maximum limits set for the car or the caravan. It is important to be aware of both the limits for the cars tow ball and the caravans hitch.
In general (and this is a guideline), the nose weight should be adjusted towards the top of the available range to aid stability of the outfit.