Article: Shiraz, with a population of around 1.4 million (2011 census), is the sixth major city of Iran. It is the capital of Fars Province, and was also a former capital of Iran. The area was greatly influenced by the Babylonian civilization, and after the emergence of the ancient Persians, soon came to be known as Persis. Persians were present in the region since the 9th century BC, and became rulers of a large empire under the reign of the Achaemenid Dynasty in the 6th century BC. The ruins of Persepolis and Pasargadae, two of the four capitals of the Achaemenid Empire, are located around the modern-day city of Shiraz.

Question: Persians have been in the Fars Province since what century?
9th century BC