Were 20% of ballot papers in the MEP selection process spoilt?

Yesterday we highlighted the fact that most women in top MEP slots received fewer votes than male rivals.  What we don't yet have from CCHQ is data on spoilt ballots.  We hope that this information will still be forthcoming.  ConservativeHome has been told that the proportion of spoilt ballot papers may be as high as 20% in one region, 15% in another.  That would be extraordinary if true and would point to the need for a much simpler voting system next time.  The 15% and 20% figures may be very wrong but we won't know if John Maples, as returning officer, doesn't follow the route of full transparency.