Input: Article: According to Eurostat, Greece's largest port by tons of goods transported in 2010 is the port of Aghioi Theodoroi, with 17.38 million tons. The Port of Thessaloniki comes second with 15.8 million tons, followed by the Port of Piraeus, with 13.2 million tons, and the port of Eleusis, with 12.37 million tons. The total number of goods transported through Greece in 2010 amounted to 124.38 million tons, a considerable drop from the 164.3 million tons transported through the country in 2007. Since then, Piraeus has grown to become the Mediterranean's third-largest port thanks to heavy investment by Chinese logistics giant COSCO. In 2013, Piraeus was declared the fastest-growing port in the world.

Now answer this question: What was the port of Piraeus declared to be in 2013?

Output: fastest-growing port in the world

Input: Article: The PlayStation 3 Slim received extremely positive reviews as well as a boost in sales; less than 24 hours after its announcement, PS3 Slim took the number-one bestseller spot on Amazon.com in the video games section for fifteen consecutive days. It regained the number-one position again one day later. PS3 Slim also received praise from PC World giving it a 90 out of 100 praising its new repackaging and the new value it brings at a lower price as well as praising its quietness and the reduction in its power consumption. This is in stark contrast to the original PS3's launch in which it was given position number-eight on their "The Top 21 Tech Screwups of 2006" list.

Now answer this question: What score did the PS3 Slim earn from PC World?

Output: 90 out of 100

Input: Article: Historians estimate that between the advent of Islam in 650CE and the abolition of slavery in the Arabian Peninsula in the mid-20th century, 10 to 18 million sub-Saharan Black Africans were enslaved by Arab slave traders and transported to the Arabian Peninsula and neighboring countries. This number far exceeded the number of slaves who were taken to the Americas. Several factors affected the visibility of descendants of this diaspora in 21st-century Arab societies: The traders shipped more female slaves than males, as there was a demand for them to serve as concubines in harems in the Arabian Peninsula and neighboring countries. Male slaves were castrated in order to serve as harem guards. The death toll of Black African slaves from forced labor was high. The mixed-race children of female slaves and Arab owners were assimilated into the Arab owners' families under the patrilineal kinship system. As a result, few distinctive Afro-Arab black communities have survived in the Arabian Peninsula and neighboring countries.

Now answer this question: Why were women slaves more popular?

Output:
for them to serve as concubines