0.1 troy oz (3.1 gram) -2018, 0.1 troy oz (3.1 gram) -2019, 0.1 troy oz (3.1 gram) -2020, 0.1 troy oz (3.1 gram) -2021, 0.25 troy oz (7.8 gram) -2018, 0.25 troy oz (7.8 gram) -2019, 0.25 troy oz (7.8 gram) -2020, 0.25 troy oz (7.8 gram) -2021, 0.5 troy oz (15.6 gram)-2018, 0.5 troy oz (15.6 gram)-2019, 0.5 troy oz (15.6 gram)-2020, 0.5 troy oz (15.6 gram)-2021, 1 troy oz (31.1 gram) -2018, 1 troy oz (31.1 gram) -2019, 1 troy oz (31.1 gram) -2020, 1 troy oz (31.1 gram)-2021, 2 troy oz (62.2 gram) – 2021, 2 troy oz (62.2 gram) -2018, 2 troy oz (62.2 gram) -2019, 2 troy oz (62.2 gram) -2020