Based on the following sorted 20 values for age, what are the possible split points? {20, 22, 24, 26, 28, 31, 32, 33, 35, 40, 42, 43, 46, 48, 49, 50, 52, 53, 55, 57}

	{20, 21, 23, 25, 27, 29.5, 31.5, 32.5, 34, 37.5, 41, 42.5, 44.5, 47, 48.5, 49.5, 51, 52.5, 54, 56}
	{0, 21, 23, 25, 27, 29.5, 31.5, 32.5, 34, 37.5, 41, 42.5, 44.5, 47, 48.5, 49.5, 51, 52.5, 54, 56}
	{21, 23, 25, 27, 29.5, 31.5, 32.5, 34, 37.5, 41, 42.5, 44.5, 47, 48.5, 49.5, 51, 52.5, 54, 56, 57}
	{21, 23, 25, 27, 29.5, 31.5, 32.5, 34, 37.5, 41, 42.5, 44.5, 47, 48.5, 49.5, 51, 52.5, 54, 56}