Landlocked developing countries (LLDC) are developing countries that are landlocked. The economic and other disadvantages experienced by such countries makes the majority of landlocked countries Least Developed Countries (LDC), with inhabitants of these countries occupying the bottom billion tier of the world's population in terms of poverty. Apart from Europe, there is not a single successful highly developed landlocked country when measured with the Human Development Index (HDI) and nine of the twelve countries with the lowest HDI scores are landlocked. Landlocked countries that rely on transoceanic trade usually suffer a cost of trade that is double of their maritime neighbours. Landlocked countries experience economic growth 6% less of their non-landlocked countries, holding other variables constant.