Oil discovery has become Nigeria's developmental Achilles' Heel, leading to a Resource Curse and a pathological dependence on oil export earnings. This has resulted in severe fiscal contraction and other economic challenges, such as unemployment, inflation, and payments imbalance. Oil-dependence also sets in motion a strong exclusionary effect on other sectors, leading to the underdevelopment of manufacturing capacity for industrial exports and export of processed agricultural goods. Malaysia progressed through Vertical Diversification from its modest agricultural base, while Nigeria's pathology of oil dependence became entrenched over time. Nigeria's oil exports in 2019 were 94.1% of total exports, oil rents amounted to 9% of GDP, and the oil and gas sector make only a small contribution to GDP. Nigeria spent $264.57b importing petroleum products during the five-year period 2015.