IIP Data: Index Of Eight Core Industries Rises In April 2021 IIP Data: Index Of Eight Core Industries Rises In April 2021 IIP Data: The month over month production of eight core industries, as captured by ICI, declined by 15.1 per cent in April 2021. IIP data for April 2021: Index showed 56 per cent growth The index of eight core industries or ICI stood at 126.7 in April 2021, showing an increase by 56.1 per cent as compared to the index of April 2020. The high growth rate in April 2021 was largely due to the low industrial production across all sectors caused by nationwide lockdown imposed to curb the spread of Corona virus last year.