Your high tax bill is likely to be down to two main factors - a high profit in the year; and the way payments on account work.
Times, Sunday Times (2009)
Economically, rations with 25% and 50% cassia substituted to cotton cake showed low variable costs and high profit.
Ouédraogo, T., Somda, J., Nianogo, AJ., Kiema, A. 2008, 'Valorisation de Cassia obtusifolia L. dans l'alimentation des ovins d'embouche en région sahélienne du Burkina Faso', Tropicultura