I am using Reuters Eikon and I want to plot Time Series Charts. I want to plot the stock prices of different firms starting in 2017 with the base 0. My problem is that only two firms are starting there. Two other firms are starting in 2018 and 2019 but they also use 2017 as a base in order to compare the development of all stock prices, which means they are starting not form zero but another value. How can I set the dates I want to refer to as a base individually? So that the firms which are starting later also start at 0.