For three years, worldwide terrorism deaths (of civilians) remained at 71-74,000 a year. Suddenly, in 2008, it dropped 24 percent. About half that decline came from the sharp drop (by about half) of terrorist attacks in Iraq. Deaths in Iraq fell even more sharply (73 percent). But Iraq, which gets most of the Western media attention for terrorism, only accounted for a third of the total terrorist attacks last year, and only ten percent of the terrorism related deaths. Even during the peak years (2006-7), Iraq only accounted for 20 percent of worldwide deaths. It turns out that there's a lot more terrorism going on than the mass media reports on. Can't blame them, though, because, when you start digging, you find that there's a lot of violence in the world that is terrorism related. Sort of, or at least somewhat.
After September 11, 2001, it suddenly became important to count terrorist attacks accurately. That was the only way to get a sense of how large, and where, the problem was. But there were problems. Take organized crime, for example, where terrorism is just another tool. Terrorism is regularly practiced by organized criminal groups. That's how the famous ones, like the mafia, or the Russian or Colombian gangs, make money and maintain discipline. What separates "terrorist organizations" from criminal gangs is ideology and goals. Organized crime groups just want to make money. Islamic terrorists, however, have other goals. In this case, imposing Islam on the entire world. Making money using criminal methods is a means to an end for them, not an end in itself.
Keep in mind that terrorist acts are a constant, and most of these actions are carried out by criminals in pursuit of a payday. Political or religious terrorists are using similar terrorism to either attract attention, as a fund raising tool, or a weapon to win concessions from governments.
So we have terrorism divided by goal (power or money). But much of the terrorism in the world is mainly about power (getting it, or holding on to it.) In many parts of the world, political power is obtained, and retained, by using gangs of terrorists. Nothing new there, the ancient Romans, and many before them, used political gangs, and terrorism, to achieve political goals. This works in democracies as well as dictatorship (Saddam had street gangs to keep hostile Iraqis under control.)
In many parts of the world, political and criminal (just for the money) terrorism are combined, as an extortion/vote getting act. Analysts often have to flip a coin to decide which act of terrorism is pure terrorism, and which is simply criminals doing business.