Not convinced of 'fair' responses
According to your figures, you sent the questionnaire to 1,005 of the 20,000 primary heads. Forty-two per cent returned it (422 heads), of whom 39 per cent (165 heads) had actually had their schools inspected. It was 84 per cent of these, just 139 heads, who thought inspection was fair.
It would be as misleading to say that only 0.7 per cent of primary heads (139 out of the total 20,000) believe that inspection is fair as it is for the chief inspector to make his assumption. It is also, in my opinion, more likely that a head who has had a "fair" inspection would return a questionnaire about it.
(Former president, National Association of Head Teachers) Orchard House Hornsea East Yorkshire