Why has there been an increase in Human Trafficking in the last 3 decades?

I need as much detail as possible, explanations on the schengen treaty, transnational organised syndicates, the collapse of the soviet union and anything else that may have contributed to it would be great, thanks in advance!Why has there been an increase in Human Trafficking in the last 3 decades?
According to the UN database,human trafficking has been increasing worldwide.The target countries are the US,Canada,Europe,Japan,South Korea,Taiwan and Singapore. In the US black list,only the Philippines was taken out of the list due to effective performance of the local government by raising the years in prison from 6 to 25.That means,the issue has not lost any interest on the US soil.Human trafficking is not only for sexual purpose,but also a lure of easy money by taking jobs in developed countries.They might come legally,but become an illegal immigrant later.And they might even have a chance to apply for citizenship.You can find them in reality at the sweatshops through out the country.Why has there been an increase in Human Trafficking in the last 3 decades?
It's not exactly an increase in trafficking. Trafficking has always been there and always been a huge market. What has changed is our awareness especially among the average citizens of the world. With current media and fighters for social justice, we are able to see what is going on better than ever before. Globalization has also change the slave trade market from regional to global which causes more publicity as well. Any time there is impoverished nation they are at risk for things like that. Former Soviet Union is one of many. Asia also has these problems as well as Africa, South America, and Latin America. Even within the United States we have women, men, and children being trafficked on a daily basis... these are American citizens even!Why has there been an increase in Human Trafficking in the last 3 decades?
All the evidence I have seen suggests that human trafficking is declining. You are under the illusion that it is increasing because of increased media attention. That very attention is what contributes to the decline.