In 200 years of holding a monopoly on trade between Britain and India, the losses of ships by the East India company were 5%. (On 5% of voyages the ship was lost from one cause or another.)

The British East India company had a monopoly on trade between Britain and the Indies from 1600 to 1813 (when the monopoly ended except for tea, which continued until 1834). During this period of over 200 years, there were about 4600 individual ship sailings from London to the East Indies (and, presumably, about the same number on the reverse voyage). About 5% of these sailings ended in the loss of the ship.

http://jds.cass.cn/Item/5607.aspx

A quick glance at East India voyage records indicates that times of war caused increased losses through enemy or privateer action.

This source: http://www.eicships.info/voyages/lostships/lostshiplistA.asp

gives all East India Company losses from 1600 -1834. Unfortunately the losses are organized alphabetically by the name of the ship, rather than by date, so it would take some statistical effort to recut the data to see loss trends by time period.

I don't know whether East India Company losses were typical of all merchant voyages. On the one hand, the East India ships were making long voyages through difficult waters. On the other hand, they were generally large, well maintained, and professionally managed ships.

By sometime before 1700 the maritime insurance market, based at Lloyds Coffee House, allowed British ship owners to insure their ships (and merchants to insure their shipped cargo), thus allowing risks to be spread.

Insurance had originated earlier, certainly in Genoa by 1600, but it was widely available in Britain by 1700.

What period are we talking about exactly? The heydays of the great Companies or....?