The agricultural sector, which employs about half of Mongolia's population, underwent major deregulation during the 1990s. In September 1991, the negdels (state-controlled collective farms) were privatized and reformed into smaller units. A combination of mismanagement and harsh weather led to higher meat prices and a depression in the agricultural processing industries. Since 1991 many herders, having no experience outside their negdels, have struggled to adapt themselves to the new economic realities. Both animal herding and crop cultivation are extremely vulnerable to the region's harsh weather and climate changes, which include occasional drought. In 1996, forest and prairie fires caused damage estimated at $1.4 billion and seriously damaged the region's environment. In the winter of 1999-2000, approximately 2.4 million animals died as a result of extremely cold and icy weather, bringing poverty and hunger to many Mongolian farmers.