In my case, as principal of Park College in Eastbourne, my salary was in fact pound;58,376 gross, which in net terms is equal to pound;36,232 per annum and not pound;71,000 as shown in your table.
I uderstand that it is simpler for you to use salaries plus on-costs, but would question whether this is clear to the vast majority of your readers. For example, do you know what your salary is including pension on-costs? In fact, I wonder if any member of the teaching profession or the public will be aware of this figure in relation to their own salary. Therefore, I would question why it is used in this context.
Phil Frier Principal, Park College Eastbourne