Try this:
African Slaves In The Arab World
http://www.aina.org/news/2006100394917.htm
Posted 2006-10-03
Over 28 Million Africans have been enslaved in the Muslim world during the past 14 centuries While much has been written concerning the Transatlantic slave trade, surprisingly little attention has been given to the Islamic slave trade across the Sahara, the Red Sea and the Indian Ocean.
While the European involvement in the Transatlantic slave trade to the Americas lasted for just over three centuries, the Arab involvement in the slave trade has lasted fourteen centuries, and in some parts of the Muslim world is still continuing to this day. A comparison of the Muslim slave trade to the American slave trade reveals some interesting contrasts.
While two out of every three slaves shipped across the Atlantic were men, the proportions were reversed in the Muslim slave trade. Two women for every man were enslaved by the Muslims.
While the mortality rate for slaves being transported across the Atlantic was as high as 10%, the percentage of slaves dying in transit in the Transsahara and East African slave trade was between 80 and 90%!
While almost all the slaves shipped across the Atlantic were for agricultural work, most of the slaves destined for the Muslim Middle East were for sexual exploitation as concubines, in harems, and for military service.
While many children were born to slaves in the Americas, and millions of their descendants are citizens in Brazil and the USA to this day, very few descendants of the slaves that ended up in the Middle East survive.
For example Criminal Victimization, 2010 no mention that I could find of the offender's race. Using Adobe Reader "Find" to search the pdf document for the word offender. And also search for the word race in a separate search.