Uzbekistan's foreign trade policy is based on import substitution. The system of multiple exchange rates combined with the highly regulated trade regime caused both imports and exports to drop each from about US$4.5 billion in 1996 to less than US$3 billion in 2002. The success of stabilization and currency liberalization in 2003 has led to significant increases in exports and imports in recent years, although imports have increased much less rapidly: while exports had more than doubled to US$15.5 by 2011, imports had risen to US$6.5 billion only, reflecting the impact of the government's import substitution policies designed to maintain hard currency reserves. Draconian tariffs, sporadic border closures, and border crossing "fees" have a negative effect on legal imports of both consumer products and capital equipment. Uzbek farmers are deprived of seasonal opportunities to sell legally their popular tomatoes and vegetables for good prices in Kazakhstan. Instead, they are forced to dump their produce at reduced prices on local markets or alternatively continue "exporting" by paying stiff bribes to border guards and customs officers. Uzbek consumers are deprived of access to low-cost Chinese goods that cross the border from Kyrgyzstan in normal times. Uzbekistan's traditional trade partners are the Commonwealth of independent States (CIS) countries, notably Russia, Ukraine, and Kazakhstan, which in aggregate account for over 40% of its exports and imports. Non-CIS partners have been increasing in importance in recent years, with Turkey, China, Iran, South Korea, and the EU being the most active. As of 2011, Russia remains the main foreign trade partner for Uzbekistan.