Plovdiv canal in the country. In that period, Plovdiv became the birthplace of Bulgaria's movement for democratic reform, which by 1989 had garnered enough support to enter government. Plovdiv has hosted specialized exhibitions of the World's Fair in 1981, 1985, and 1991. The population by permanent address for the municipality of Plovdiv for 2007 is 380,682, which makes it the second in population in the nation. According to the data of the National Institute of Statistics (NSI), the people who actually live in Plovdiv are 346,790. According to the 2012 census, 339,077 live within the city limits and 403,153 in the
Plovdiv the year. Mists are common in the cooler months, especially along the banks of the Maritsa. On average there are 33 days with mist during the year. The history of Plovdiv spans more than eight millennia. Numerous nations have left their traces on the cultural layers of the city. The earliest signs of habitation on the territory of Plovdiv date as far back as the 6th millennium BCE. Plovdiv has settlement traces including necropolises dating from the Neolithic era, roughly 6000–5000 BCE, like the mounds Yasa Tepe 1 in Philipovo district and Yasa Tepe 2 in Lauta park. Archaeologists have