static async Task <YahooModel> grabData(String s)
            {
                using (var client = new HttpClient())
                {
                    Console.WriteLine("starting" + s);
                    String url      = "https://financialmodelingprep.com/api/v3/historical-price-full/" + s.ToUpper() + "?apikey=4992d801ad7f4e2b40e12d596b5dbcae&from=1900-10-10";
                    var    response = await client.GetStringAsync(url);

                    YahooModel returnObj = JsonConvert.DeserializeObject <YahooModel>(response);
                    Console.WriteLine("ending" + s);
                    return(returnObj);
                }
            }
 String percentChange(YahooModel m)
 {