With the increase of mining depth, the gas content of coal seam increases. Users of this data set should consider it in the context of environmental impact assessments regarding methane emissions from coal mining activities. When using the data, they should adopt the IPCC's 'Tier 2' approach with regional average methane coefficients for calculation, as applied in the creation of the dataset. Due attention should be given to technological changes since 2000 which may have altered the efficiency of methane capture and utilization in coal mines. If used for comparative studies or temporal analyses, adjustments may be required to account for technological and methodological advancements over time.