Question: 2023年05月01日到2024年01月30日，润泽科技的下行偏差是多少？（默认目标收益率为0；无需年化）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: DD = \sqrt{1 / N * \sum_{t=1}^{N} min(r_t - rf, 0)^2}
Data:
date,close
2023-04-28,60.0
2023-05-04,58.78
2023-05-05,57.58
2023-05-08,57.75
2023-05-09,57.5
2023-05-10,56.05
2023-05-11,55.05
2023-05-12,54.92
2023-05-15,55.85
2023-05-16,56.59
2023-05-17,55.44
2023-05-18,55.58
2023-05-19,55.41
2023-05-22,54.18
2023-05-23,54.5
2023-05-24,29.86
2023-05-25,30.09
2023-05-26,31.79
2023-05-29,32.06
2023-05-30,32.6
2023-05-31,32.36
2023-06-01,32.35
2023-06-02,32.65
2023-06-05,32.23
2023-06-06,32.4
2023-06-07,32.18
2023-06-08,31.93
2023-06-09,33.56
2023-06-12,33.2
2023-06-13,34.55
2023-06-14,35.31
2023-06-15,33.69
2023-06-16,33.85
2023-06-19,36.08
2023-06-20,36.91
2023-06-21,34.8
2023-06-26,32.67
2023-06-27,32.69
2023-06-28,30.83
2023-06-29,30.4
2023-06-30,30.76
2023-07-03,31.05
2023-07-04,32.24
2023-07-05,31.42
2023-07-06,30.62
2023-07-07,30.42
2023-07-10,29.65
2023-07-11,29.4
2023-07-12,28.75
2023-07-13,28.53
2023-07-14,29.07
2023-07-17,28.74
2023-07-18,28.56
2023-07-19,28.67
2023-07-20,28.22
2023-07-21,27.89
2023-07-24,28.1
2023-07-25,28.44
2023-07-26,28.06
2023-07-27,29.36
2023-07-28,28.94
2023-07-31,28.4
2023-08-01,28.03
2023-08-02,27.68
2023-08-03,27.42
2023-08-04,28.6
2023-08-07,27.59
2023-08-08,27.69
2023-08-09,27.47
2023-08-10,27.98
2023-08-11,27.88
2023-08-14,28.17
2023-08-15,26.87
2023-08-16,23.48
2023-08-17,22.93
2023-08-18,22.65
2023-08-21,23.05
2023-08-22,23.61
2023-08-23,23.01
2023-08-24,23.07
2023-08-25,23.29
2023-08-28,23.48
2023-08-29,24.66
2023-08-30,25.89
2023-08-31,25.7
2023-09-01,25.5
2023-09-04,26.42
2023-09-05,26.4
2023-09-06,26.25
2023-09-07,25.91
2023-09-08,26.25
2023-09-11,25.7
2023-09-12,25.67
2023-09-13,24.83
2023-09-14,24.6
2023-09-15,24.39
2023-09-18,24.49
2023-09-19,23.89
2023-09-20,24.28
2023-09-21,24.17
2023-09-22,24.85
2023-09-25,24.51
2023-09-26,24.3
2023-09-27,24.53
2023-09-28,24.35
2023-10-09,24.27
2023-10-10,24.31
2023-10-11,24.53
2023-10-12,24.5
2023-10-13,24.14
2023-10-16,23.66
2023-10-17,23.85
2023-10-18,23.18
2023-10-19,22.78
2023-10-20,21.87
2023-10-23,20.8
2023-10-24,21.13
2023-10-25,22.24
2023-10-26,23.2
2023-10-27,23.29
2023-10-30,23.55
2023-10-31,23.35
2023-11-01,22.94
2023-11-02,22.26
2023-11-03,22.73
2023-11-06,23.52
2023-11-07,24.43
2023-11-08,24.7
2023-11-09,25.17
2023-11-10,24.16
2023-11-13,25.06
2023-11-14,26.12
2023-11-15,25.92
2023-11-16,26.5
2023-11-17,27.06
2023-11-20,27.6
2023-11-21,26.65
2023-11-22,26.74
2023-11-23,26.8
2023-11-24,26.48
2023-11-27,26.34
2023-11-28,27.1
2023-11-29,26.43
2023-11-30,27.0
2023-12-01,26.7
2023-12-04,26.9
2023-12-05,25.93
2023-12-06,26.02
2023-12-07,26.4
2023-12-08,27.47
2023-12-11,27.99
2023-12-12,27.7
2023-12-13,26.92
2023-12-14,26.64
2023-12-15,26.7
2023-12-18,25.88
2023-12-19,25.8
2023-12-20,25.46
2023-12-21,25.44
2023-12-22,24.55
2023-12-25,24.72
2023-12-26,24.12
2023-12-27,24.79
2023-12-28,24.86
2023-12-29,25.37
2024-01-02,24.54
2024-01-03,24.47
2024-01-04,24.18
2024-01-05,23.7
2024-01-08,23.08
2024-01-09,22.9
2024-01-10,22.41
2024-01-11,23.13
2024-01-12,22.7
2024-01-15,22.29
2024-01-16,22.22
2024-01-17,21.67
2024-01-18,21.79
2024-01-19,21.99
2024-01-22,20.5
2024-01-23,20.77
2024-01-24,20.83
2024-01-25,21.5
2024-01-26,21.0
2024-01-29,19.97
2024-01-30,20.37

Indicator data:
Answer: 0.0386