Question: 芒果超媒在2023年09月08日到2024年04月21日期间，收盘价跌破20日加权移动平均线共几次？（权重取 1, 2, ..., n）使用不复权价格，写出指标公式，搜集原始数据，计算得出答案，保留四位小数。注意列出原始数据和关键计算过程。
Formula: WMA_n = \sum_{i=0}^{n-1} (n-i) * P_{t-i} / \sum_{j=1}^{n} j
Data:
date,close,low,high,open
2023-08-14,33.27,32.37,33.32,32.5
2023-08-15,32.25,32.01,33.3,33.27
2023-08-16,30.61,30.25,32.2,32.07
2023-08-17,31.11,30.18,31.29,30.83
2023-08-18,29.22,29.2,30.84,30.69
2023-08-21,28.92,28.92,29.75,29.14
2023-08-22,29.32,28.44,29.5,29.18
2023-08-23,28.75,28.7,29.29,29.29
2023-08-24,29.2,28.76,29.73,29.0
2023-08-25,28.66,28.49,29.15,28.9
2023-08-28,28.78,28.71,30.79,30.38
2023-08-29,29.53,28.55,29.78,28.67
2023-08-30,29.94,29.48,30.2,29.75
2023-08-31,29.54,29.5,30.06,29.75
2023-09-01,29.47,29.22,29.74,29.41
2023-09-04,29.7,29.32,29.83,29.47
2023-09-05,29.36,29.21,29.65,29.64
2023-09-06,28.88,28.75,29.21,29.15
2023-09-07,28.22,28.16,28.9,28.85
2023-09-08,28.0,27.64,28.3,28.18
2023-09-11,29.0,28.19,29.2,28.25
2023-09-12,28.48,28.37,29.03,28.99
2023-09-13,27.93,27.71,28.5,28.42
2023-09-14,27.82,27.57,28.0,27.81
2023-09-15,27.65,27.54,28.19,27.83
2023-09-18,27.67,27.29,28.05,27.65
2023-09-19,27.0,26.93,27.82,27.82
2023-09-20,26.81,26.81,27.2,26.88
2023-09-21,26.48,26.45,26.95,26.82
2023-09-22,27.39,26.41,27.57,26.52
2023-09-25,26.92,26.6,27.53,27.5
2023-09-26,27.79,26.9,28.0,26.97
2023-09-27,28.27,27.5,28.5,27.71
2023-09-28,28.31,27.96,28.42,28.39
2023-10-09,27.69,27.45,28.26,28.16
2023-10-10,27.9,27.71,28.14,27.79
2023-10-11,28.7,27.83,28.94,28.03
2023-10-12,28.33,28.16,28.9,28.8
2023-10-13,27.47,27.3,28.28,28.16
2023-10-16,27.0,26.8,27.62,27.52
2023-10-17,26.95,26.87,27.29,27.0
2023-10-18,26.49,26.18,26.99,26.92
2023-10-19,26.3,26.23,26.73,26.39
2023-10-20,25.89,25.79,26.43,26.28
2023-10-23,25.34,25.06,25.88,25.8
2023-10-24,25.9,25.34,26.19,25.5
2023-10-25,24.43,24.32,26.22,26.21
2023-10-26,24.55,24.23,24.85,24.37
2023-10-27,25.12,24.05,25.35,24.4
2023-10-30,25.36,24.77,25.45,25.0
2023-10-31,25.29,25.0,25.97,25.6
2023-11-01,25.25,25.02,25.88,25.3
2023-11-02,25.55,25.16,26.21,25.32
2023-11-03,25.74,24.8,26.09,25.21
2023-11-06,28.3,25.92,28.46,26.0
2023-11-07,28.2,27.86,28.68,28.3
2023-11-08,29.25,27.89,30.04,27.89
2023-11-09,29.05,28.59,29.33,28.9
2023-11-10,28.75,28.21,29.25,28.82
2023-11-13,28.74,28.51,29.29,29.08
2023-11-14,28.47,28.3,28.89,28.5
2023-11-15,28.36,28.08,28.75,28.74
2023-11-16,28.12,27.81,28.59,28.26
2023-11-17,27.97,27.73,28.38,27.95
2023-11-20,27.71,27.57,28.18,27.88
2023-11-21,27.9,27.61,28.37,27.78
2023-11-22,28.07,27.61,28.43,27.68
2023-11-23,27.51,26.83,27.73,27.65
2023-11-24,26.94,26.77,27.8,27.45
2023-11-27,26.28,25.93,26.61,26.58
2023-11-28,26.01,25.75,26.25,26.25
2023-11-29,25.84,25.7,26.17,26.1
2023-11-30,25.81,25.65,26.15,25.75
2023-12-01,26.9,25.73,27.15,25.84
2023-12-04,27.06,26.49,27.5,26.75
2023-12-05,27.59,26.31,29.25,26.96
2023-12-06,28.7,26.72,29.05,27.1
2023-12-07,29.76,28.05,29.98,28.56
2023-12-08,30.26,29.3,30.95,29.47
2023-12-11,30.24,29.75,31.32,29.98
2023-12-12,30.2,29.82,30.72,30.33
2023-12-13,30.69,30.01,31.31,30.09
2023-12-14,29.1,28.9,30.6,30.44
2023-12-15,29.28,28.36,29.99,29.53
2023-12-18,28.54,28.45,29.33,28.77
2023-12-19,28.65,28.15,29.05,28.53
2023-12-20,27.71,27.61,28.89,28.68
2023-12-21,27.7,27.2,27.94,27.4
2023-12-22,25.6,25.3,27.65,27.59
2023-12-25,25.79,25.18,26.28,25.6
2023-12-26,25.03,24.95,26.19,26.02
2023-12-27,24.5,24.4,25.34,25.18
2023-12-28,24.81,24.21,25.03,24.4
2023-12-29,25.2,24.64,25.65,24.71
2024-01-02,24.97,24.91,25.6,25.38
2024-01-03,25.49,24.62,25.7,24.83
2024-01-04,25.01,24.82,25.36,25.36
2024-01-05,24.16,24.01,24.92,24.91
2024-01-08,23.54,23.42,24.22,24.0
2024-01-09,23.12,22.76,23.74,23.63
2024-01-10,22.49,22.32,23.0,23.0
2024-01-11,22.97,22.3,23.15,22.53
2024-01-12,22.44,22.34,22.95,22.9
2024-01-15,22.03,22.0,22.67,22.4
2024-01-16,22.11,21.61,22.13,21.94
2024-01-17,21.55,21.54,22.1,22.0
2024-01-18,21.73,20.93,21.83,21.44
2024-01-19,22.25,21.83,22.75,22.22
2024-01-22,21.13,20.95,22.28,22.02
2024-01-23,21.87,20.95,22.03,21.01
2024-01-24,22.6,21.92,22.95,22.75
2024-01-25,23.22,22.15,23.28,22.37
2024-01-26,22.82,22.75,23.41,23.07
2024-01-29,22.4,22.23,23.01,22.77
2024-01-30,21.69,21.62,22.47,22.33
2024-01-31,21.4,21.4,22.14,21.58
2024-02-01,21.74,20.61,22.25,21.34
2024-02-02,20.96,20.0,22.2,21.72
2024-02-05,20.4,19.22,20.88,20.71
2024-02-06,22.36,19.86,22.37,20.03
2024-02-07,22.79,22.1,22.82,22.33
2024-02-08,23.52,22.46,23.53,23.0
2024-02-19,23.95,23.5,24.28,24.18
2024-02-20,23.72,23.27,24.02,23.95
2024-02-21,23.57,23.05,24.21,23.21
2024-02-22,23.89,23.22,24.02,23.27
2024-02-23,24.15,23.46,24.15,24.0
2024-02-26,23.79,23.46,24.18,24.01
2024-02-27,24.82,23.56,24.88,23.62
2024-02-28,23.32,23.31,25.09,24.82
2024-02-29,24.78,23.4,24.79,23.5
2024-03-01,25.63,24.55,25.81,24.87
2024-03-04,25.2,24.79,25.64,25.5
2024-03-05,24.88,24.63,25.3,25.0
2024-03-06,24.81,24.52,25.15,24.73
2024-03-07,23.95,23.87,24.98,24.85
2024-03-08,24.17,23.8,24.31,23.95
2024-03-11,24.52,23.94,24.64,24.14
2024-03-12,24.87,24.31,24.91,24.65
2024-03-13,24.96,24.67,25.38,24.87
2024-03-14,24.51,24.19,24.84,24.65
2024-03-15,24.41,24.0,24.54,24.4
2024-03-18,25.1,24.34,25.2,24.53
2024-03-19,24.99,24.98,25.91,25.25
2024-03-20,26.58,24.99,26.58,24.99
2024-03-21,26.21,26.18,27.12,26.88
2024-03-22,26.79,25.75,27.09,26.22
2024-03-25,25.42,25.39,27.5,27.44
2024-03-26,25.1,24.53,25.46,25.2
2024-03-27,24.15,24.11,25.18,25.0
2024-03-28,24.47,24.08,24.8,24.1
2024-03-29,24.31,23.75,24.55,24.4
2024-04-01,25.28,24.34,25.33,24.44
2024-04-02,24.84,24.53,25.28,25.19
2024-04-03,24.13,23.97,24.7,24.66
2024-04-08,23.55,23.55,24.06,24.06
2024-04-09,24.04,23.48,24.15,23.7
2024-04-10,23.14,23.0,24.0,24.0
2024-04-11,23.27,22.94,23.68,22.99
2024-04-12,22.94,22.88,23.36,23.2
2024-04-15,23.3,22.85,23.76,22.85
2024-04-16,22.63,22.52,23.47,23.09
2024-04-17,23.42,22.83,23.42,22.83
2024-04-18,23.34,22.91,23.75,23.31
2024-04-19,23.54,23.08,23.65,23.16

Indicator data:
date,20日,close
2023-09-08,29.163857142857147,28.0
2023-09-11,29.103238095238098,29.0
2023-09-12,29.013428571428573,28.48
2023-09-13,28.88919047619048,27.93
2023-09-14,28.767238095238095,27.82
2023-09-15,28.644761904761904,27.65
2023-09-18,28.531666666666673,27.67
2023-09-19,28.360714285714284,27.0
2023-09-20,28.182714285714287,26.81
2023-09-21,27.982523809523812,26.48
2023-09-22,27.881952380952377,27.39
2023-09-25,27.742666666666672,26.92
2023-09-26,27.695095238095238,27.79
2023-09-27,27.70152380952381,28.27
2023-09-28,27.719714285714286,28.31
2023-10-09,27.684714285714286,27.69
2023-10-10,27.678190476190476,27.9
2023-10-11,27.75642857142857,28.7
2023-10-12,27.802571428571433,28.33
2023-10-13,27.76942857142857,27.47
2023-10-16,27.695095238095234,27.0
2023-10-17,27.620761904761903,26.95
2023-10-18,27.51238095238095,26.49
2023-10-19,27.395380952380954,26.3
2023-10-20,27.247095238095234,25.89
2023-10-23,27.055619047619043,25.34
2023-10-24,26.928476190476193,25.9
2023-10-25,26.669761904761906,24.43
2023-10-26,26.434714285714282,24.55
2023-10-27,26.26471428571428,25.12
2023-10-30,26.124047619047616,25.36
2023-10-31,25.986380952380955,25.29
2023-11-01,25.852666666666664,25.25
2023-11-02,25.759619047619044,25.55
2023-11-03,25.697619047619046,25.74
2023-11-06,25.891666666666666,28.3
2023-11-07,26.07328571428571,28.2
2023-11-08,26.35347619047619,29.25
2023-11-09,26.612000000000002,29.05
2023-11-10,26.838523809523807,28.75
2023-11-13,27.058,28.74
2023-11-14,27.243476190476187,28.47
2023-11-15,27.411238095238094,28.36
2023-11-16,27.547238095238097,28.12
2023-11-17,27.66028571428571,27.97
2023-11-20,27.738666666666667,27.71
2023-11-21,27.823857142857143,27.9
2023-11-22,27.915714285714284,28.07
2023-11-23,27.936904761904763,27.51
2023-11-24,27.88971428571429,26.94
2023-11-27,27.771,26.28
2023-11-28,27.622190476190475,26.01
2023-11-29,27.453761904761905,25.84
2023-11-30,27.279666666666667,25.81
2023-12-01,27.208142857142857,26.9
2023-12-04,27.146333333333335,27.06
2023-12-05,27.140904761904768,27.59
2023-12-06,27.244095238095237,28.7
2023-12-07,27.45085714285714,29.76
2023-12-08,27.701857142857143,30.26
2023-12-11,27.943761904761903,30.24
2023-12-12,28.174714285714288,30.2
2023-12-13,28.44409523809524,30.69
2023-12-14,28.55095238095238,29.1
2023-12-15,28.67028571428571,29.28
2023-12-18,28.712904761904763,28.54
2023-12-19,28.762047619047618,28.65
2023-12-20,28.718095238095245,27.71
2023-12-21,28.67490476190476,27.7
2023-12-22,28.430809523809526,25.6
2023-12-25,28.211190476190477,25.79
2023-12-26,27.921523809523812,25.03
2023-12-27,27.58604761904762,24.5
2023-12-28,27.28647619047619,24.81
2023-12-29,27.028809523809525,25.2
2024-01-02,26.75733333333333,24.97
2024-01-03,26.54533333333334,25.49
2024-01-04,26.297619047619044,25.01
2024-01-05,25.986523809523806,24.16
2024-01-08,25.643047619047618,23.54
2024-01-09,25.29157142857143,23.12
2024-01-10,24.913999999999998,22.49
2024-01-11,24.618857142857138,22.97
2024-01-12,24.310000000000002,22.44
2024-01-15,23.993809523809524,22.03
2024-01-16,23.719761904761903,22.11
2024-01-17,23.423,21.55
2024-01-18,23.177190476190482,21.73
2024-01-19,23.009380952380955,22.25
2024-01-22,22.760857142857144,21.13
2024-01-23,22.604095238095237,21.87
2024-01-24,22.53552380952381,22.6
2024-01-25,22.537571428571425,23.22
2024-01-26,22.50761904761905,22.82
2024-01-29,22.44714285714286,22.4
2024-01-30,22.33238095238096,21.69
2024-01-31,22.20561904761905,21.4
2024-02-01,22.13071428571429,21.74
2024-02-02,21.997095238095234,20.96
2024-02-05,21.825380952380957,20.4
2024-02-06,21.855285714285714,22.36
2024-02-07,21.929761904761904,22.79
2024-02-08,22.072333333333333,23.52
2024-02-19,22.253238095238093,23.95
2024-02-20,22.405047619047618,23.72
2024-02-21,22.534523809523805,23.57
2024-02-22,22.68752380952381,23.89
2024-02-23,22.854142857142858,24.15
2024-02-26,22.974952380952384,23.79
2024-02-27,23.18652380952381,24.82
2024-02-28,23.237666666666666,23.32
2024-02-29,23.42095238095238,24.78
2024-03-01,23.674809523809525,25.63
2024-03-04,23.876238095238097,25.2
2024-03-05,24.035857142857147,24.88
2024-03-06,24.177,24.81
2024-03-07,24.221380952380954,23.95
2024-03-08,24.274571428571427,24.17
2024-03-11,24.34952380952381,24.52
2024-03-12,24.440857142857144,24.87
2024-03-13,24.519476190476187,24.96
2024-03-14,24.542857142857137,24.51
2024-03-15,24.548523809523807,24.41
2024-03-18,24.615666666666666,25.1
2024-03-19,24.666857142857143,24.99
2024-03-20,24.863428571428578,26.58
2024-03-21,25.01042857142857,26.21
2024-03-22,25.201619047619044,26.79
2024-03-25,25.249761904761904,25.42
2024-03-26,25.25966666666667,25.1
2024-03-27,25.1777619047619,24.15
2024-03-28,25.12238095238095,24.47
2024-03-29,25.053238095238097,24.31
2024-04-01,25.08276190476191,25.28
2024-04-02,25.07,24.84
2024-04-03,24.989809523809527,24.13
2024-04-08,24.85761904761905,23.55
2024-04-09,24.774,24.04
2024-04-10,24.605285714285714,23.14
2024-04-11,24.455523809523804,23.27
2024-04-12,24.28195238095238,22.94
2024-04-15,24.15228571428571,23.3
2024-04-16,23.964571428571432,22.63
2024-04-17,23.86057142857143,23.42
2024-04-18,23.75695238095238,23.34
2024-04-19,23.680238095238096,23.54

Answer: 9.0