What is the proportion of exercisable shares among the total outstanding shares as of August 29, 2019?
{"Outstanding as of August 30, 2018": {"Number of Shares": 18, "Weighted-Average Exercise Price Per Share": 23.38, "Weighted-Average Remaining Contractual Life (In Years)": "", "Aggregate Intrinsic Value": ""}, "Granted": {"Number of Shares": "\u2014", "Weighted-Average Exercise Price Per Share": 44.3, "Weighted-Average Remaining Contractual Life (In Years)": "", "Aggregate Intrinsic Value": ""}, "Exercised": {"Number of Shares": -5, "Weighted-Average Exercise Price Per Share": 17.5, "Weighted-Average Remaining Contractual Life (In Years)": "", "Aggregate Intrinsic Value": ""}, "Canceled or expired": {"Number of Shares": -1, "Weighted-Average Exercise Price Per Share": 22.6, "Weighted-Average Remaining Contractual Life (In Years)": "", "Aggregate Intrinsic Value": ""}, "Outstanding as of August 29, 2019": {"Number of Shares": 12.0, "Weighted-Average Exercise Price Per Share": 25.94, "Weighted-Average Remaining Contractual Life (In Years)": 4.3, "Aggregate Intrinsic Value": 220.0}, "Exercisable as of August 29, 2019": {"Number of Shares": 7.0, "Weighted-Average Exercise Price Per Share": 25.37, "Weighted-Average Remaining Contractual Life (In Years)": 3.7, "Aggregate Intrinsic Value": 143.0}, "Unvested as of August 29, 2019": {"Number of Shares": 5.0, "Weighted-Average Exercise Price Per Share": 26.94, "Weighted-Average Remaining Contractual Life (In Years)": 5.5, "Aggregate Intrinsic Value": 77.0}}
exercisable_as_of_aug_29_2019 = df["Exercisable as of August 29, 2019"]["Number of Shares"]
outstanding_as_of_aug_29_2019 = df["Outstanding as of August 29, 2019"]["Number of Shares"]
answer = exercisable_as_of_aug_29_2019 / outstanding_as_of_aug_29_2019