India's infrastructure output jumped 7.9% in September on a year-on-year basis, government data showed on Wednesday, reflecting strong growth in coal, refinery products, steel and iron ore.The core sector output rose as compared with 3.1% growth in the same month last year, according to the data .The index, which tracks activity across nine sectors and makes up about a third of the country's industrial production, rose at a revised 5.9% in August.Iron ore production recorded the highest growth among the eight core industries, rising 18.4% year-on-year in September, followed by electricity generation, which grew 11.4%.