How many years from 1998 to 2015?

How long have cymbals been around? What is the origin of the surname Worthington? What are the names of the ranks in ancient rome? What happened in 1453 that was a turning point? Total number of years for the crusades? What is the cattle frontier? What did US actions in Western Europe during the Cold War consistent with US values? Which of the following EXCEPT were created or invented during the early Middle Ages? Why ottoman empire was called 'sick man of Europe'? Where does cut to the chase originate from? What was the function of a procurator in the roman empire? What work is considered the first work of literary criticism in Western culture? What was the problem in the Crusades? What is the meaning of the quote 'The devil is in the details'? What areas of the world did Romans take over? When was The Fall of Rome created? What group held most of the power in medieval Europe? In witch century was the year 1999? Who are known as the knights of the round table? Why was European renaissance important?