Answer based on context:

In 1552 Charles V had borrowed over 4 million ducats, with the Metz campaign alone costing 2.5 million ducats. Shipments of treasure from the Indies totalled over two million ducats between 1552-53. By 1554, the cash deficit for the year was calculated to be over 4.3 million ducats, even after all tax receipts for the six ensuing years had been pledged and the proceeds spent in advance. Credit at this point began costing the crown 43 percent interest . By 1557 the crown was refusing payment from the Indies since even this was required for payment of the war effort . French finances during the war were mainly financed by the increase in the taille tax, as well as indirect taxes like the gabelle and customs fees. The French monarchy also resorted to heavy borrowings during the war from financiers at rates of 10-16 percent interest. The taille was estimated in collection for 1551 at around six million livres. During the 1550s, Spain had an estimated military manpower of around 150,000 soldiers, whereas France had an estimated manpower of 50,000.

How many more millions of ducats did Charles V borrow over what the Metz campaign cost?
1.5