void OnTapped()
        {
            //checks that the database has elements before proceeding
            if (QueryList.Count() > 0)
            {
                //adds first category
                HistoricalStandingsDataList.Add(new HistoricalStandingTitleModel {
                    Title = QueryList.First().TournamentName
                });

                //checks for each element if there already exists a matching category, adds it if not
                for (int i = 1; i < QueryList.Count(); i++)
                {
                    if (QueryList.ElementAt(i).TournamentName != QueryList.ElementAt(i - 1).TournamentName)
                    {
                        bool add = true;
                        foreach (var item in HistoricalStandingsDataList)
                        {
                            if (item.Title.ToUpper() == QueryList.ElementAt(i).TournamentName.ToUpper())
                            {
                                add = false;
                            }
                        }
                        if (add)
                        {
                            HistoricalStandingsDataList.Add(new HistoricalStandingTitleModel {
                                Title = QueryList.ElementAt(i).TournamentName
                            });
                        }
                    }
                }
                ShowListView = !_showListView;
                if (_showListView)
                {
                    ArrowImage = "up_arrow.png";
                }
                else
                {
                    ArrowImage = "down_arrow.png";
                }
            }
        }