What are the main reasons for the high number of (a) grade 1 class of works being performed in KwaZulu-Natal (KZN) compared to the other eight provinces, (b) consolidated ownership profile (grade 1) in KZN compared to other provinces and (c) all grades of registration in KZN compared to the other provinces as listed on page 36 of the Construction Industry Development Board Annual Report 2011-12?