By the end of the war English privateering had devastated the Spanish private merchant marine. The most famous pirates lauded by English literature and propaganda tended to attack fishing vessels or boats with small value for the Spanish crown. Spanish prizes though were taken at an attritional rate; nearly 1,000 were captured by the wars end, and there was on average a declared value of approximately £100,000-£200,000 for every year of the war. In addition for every Spanish prize brought back, another was either burned or scuttled, and the presence of so many English corsairs even deterred Spanish merchantman from putting to sea. This all later resulted in Spanish and Portuguese commerce being carried on Dutch and English ships which in itself created competition. Nevertheless, throughout the war Spain's important treasure fleets had been kept safe by their convoy system.