You will be given a definition of a task first, then some input of the task.
This task involves creating answers to complex questions, from a given passage. Answering these questions, typically involve understanding multiple sentences. Make sure that your answer has the same type as the "answer type" mentioned in input. The provided "answer type" can be of any of the following types: "span", "date", "number". A "span" answer is a continuous phrase taken directly from the passage or question. You can directly copy-paste the text from the passage or the question for span type answers. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words. A "number" type answer can include a digit specifying an actual value. For "date" type answers, use DD MM YYYY format e.g. 11 Jan 1992. If full date is not available in the passage you can write partial date such as 1992 or Jan 1992. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words.

Passage: The site of the battle is located near U.S. Highway 56, about three miles east of Baldwin City, and is partially within Robert Hall Pearson Memorial Park, designated by the state of Kansas in honor of one of Brown and Shore's fighters who gave a handwritten account of the battle. Signs placed throughout the battle site point out where the battle began and ended. Efforts are underway to preserve both the Pearson Memorial Park and the Ivan Boyd Prairie Preserve across the road. In 1970, to commemorate the 100th anniversary of the founding of Baldwin City, Baker University professor and playwright Don Mueller and Phyllis E. Braun, Business Manager, produced a musical play entitled The Ballad Of Black Jack to tell the story of the events that led up to the battle. The Ballad Of Black Jack played as part of the city's Maple Leaf Festival from 1970-83 and again from 2001-05. It also played in nearby Lawrence in 1986 and in 2006 and 2007 as a part of Lawrence's Civil War On The Western Frontier program. In 2012 the National Park Service designated the battlefield a National Historic Landmark.
Question: How many years did The Ballad Of Black Jack play as part of the Maple Leaf Festival?
Answer type: Number
Output:
19.