Solon's economic reforms need to be understood in the context of the primitive, subsistence economy that prevailed both before and after his time. Most Athenians were still living in rural settlements right up to the Peloponnesian War. Opportunities for trade even within the Athenian borders were limited. The typical farming family, even in classical times, barely produced enough to satisfy its own needs. Opportunities for international trade were minimal. It has been estimated that, even in Roman times, goods rose 40% in value for every 100 miles they were carried over land, but only 1.3% for the same distance were they carried by ship and yet there is no evidence that Athens possessed any merchant ships until around 525 BC. Until then, the narrow warship doubled as a cargo vessel. Athens, like other Greek city states in the 7th Century BC, was faced with increasing population pressures and by about 525 BC it was able to feed itself only in 'good years'.