From the following data, find the 2019 Net Sales index number (as a %), using 2015 as the base year. (Round to the nearest tenth percent.) International Industries-5 Year Selected Financial Data 2018 Net Sales 2019 Net Income 2017 2016 491,990 459,620 488,960 461,280 431,300 42,470 43,780 47,590 51,730 51,730 Total Assets 141,540 148,990 156,830 156,830 146,570 2015