public IActionResult Relative(string metric, string option = ViewModelService.NORM_POPULATION)
        {
            PlotViewModel model = _covidService.GetRelativeViewModel(metric, option, ViewModelService.MIN_DEATHS_MILLION);

            ViewData["Metric"]          = metric;
            ViewData["Method"]          = System.Reflection.MethodBase.GetCurrentMethod().Name;
            ViewData["Title"]           = "Relative";
            ViewData["YLabel"]          = metric + " / " + option;
            ViewData["TooltipDecimals"] = 2;
            ViewData["YMin"]            = 1;
            ViewData["YType"]           = "linear";
            ViewData["YTickInterval"]   = 1;
            ViewData["XLabel"]          = $"Days from 1 {metric} / million";

            return(View("Plot", model));
        }