Bituminous coal
According to the Australian Bureau of Agricultural and Resource Economics and Sciences in 2011 the economically demonstrated reserves to production ratios for bituminous coal and lignite in Australia are 111 years and 539 years respectively. However, these figures do not account for growth in production. Bituminous coal exports from Australia have been growing at a rate of 5% (on average during the last 20 years). If this rate of growth would-be maintained to extinction all current economically demonstrated black coal in the country would be depleted in under 40 years. However, continued growth at that rate is unlikely to occur for such a long period, and this estimate does not reflect growth in the demonstrated resource. Explorations in the last decade has resulted in a significant increase in inferred coal resources which are now almost double the economically demonstrated resource.