The .csv export of the Item Sales by Voucher report has 2 columns with figures, but neither column adds up to the total vouchers sold:
(1) The "Experience Price" column appears to have the cost of the first item in the sale, which is not always a voucher; and
(2) When more than one voucher is purchased in one sale the first voucher cost appears twice in the "Experience" column, and the total of the multiple vouchers appears twice in the "Total" column.
So the total of neither the "Experience Price" column, nor the "Total" column adds up to the total of vouchers sold in the chosen period.
I am hoping this is an easy-ish fix as it is very frustrating attempting to reconcile both vouchers sold and vouchers outstanding with the figures in the accounting program.