New Delhi, Aug 31 : The combined index of eight core industries (ICI) increased by 8 per cent (provisional) in July 2023 as compared to the same month last year. The production of coal, steel, natural gas, cement, electricity, refinery products, fertilisers and crude oil increased in July 2023 over the corresponding month of last year. The eight core industries comprise 40.27 per cent of the weight of items included in the Index of Industrial Production (IIP). Meanwhile, final growth rate of index of eight core industries for April 2023 is revised to 4.6 per cent from its provisional level 3.5 per cent. Coal production increased by 14.9 per cent in July 2023 over July 2022, crude oil production rose by 2.1 per cent, natural gas production went up by 8.9 per cent, and petroleum refinery production increased by 3.6 per cent. Fertiliser production also rose by 3.3 per cent in July 2023 over July 2022, steel production went up by 13.5 per cent, cement production increased by 7.1 per cent and electricity generation rose by 6.9 per cent. /IANS