data
| Date | L，LF日 | L，LF晚 | L，LF夜 |
|---|---|---|---|
| dB | dB | dB | |
| 2021-Q4 | 27.0 | 19.0 | 21.5 |
| 2021-Q3 | 25.5 | 21.6 | 20.6 |
| 2021-Q2 | 23.8 | 15.8 | 16.7 |
| 2021-Q1 | 25.0 | 19.2 | 19.3 |
| 2020-Q4 | 24.2 | 20.2 | 17.5 |
| 2020-Q3 | 27.6 | 21.5 | 20.5 |
| 2020-Q2 | 27.3 | 23.5 | 21.2 |
| 2020-Q1 | 26.3 | 21.9 | 22.1 |
| 2019-Q4 | 27.2 | 17.7 | 18.2 |
| 2019-Q3 | 29.0 | 22.0 | 21.6 |
| 2019-Q2 | 30.8 | 26.9 | 29.2 |
| 2019-Q1 | 29.4 | 25.7 | 25.4 |
| 2018-Q4 | 32.7 | 19.2 | 18.2 |
| 2018-Q3 | 29.5 | 23.0 | 22.8 |
| 2018-Q2 | 30.8 | 27.6 | 27.0 |
| 2018-Q1 | 41.8 | 35.5 | 36.2 |
| 2017-Q4 | 37.2 | 34.1 | 33.2 |
| 2017-Q3 | 29.7 | 25.0 | 25.0 |
| 2017-Q2 | 38.3 | 32.0 | 33.6 |
| 2017-Q1 | 34.0 | 25.0 | 25.0 |
| 2016-Q4 | 36.5 | 26.9 | 27.4 |
| 2016-Q3 | 33.1 | 25 | 25 |
| 2016-Q2 | 32.2 | 25.8 | 25.6 |
| 2016-Q1 | 34.9 | 30 | 30 |
| 2015-Q4 | 33.8 | 30.1 | 30.1 |
| 2015-Q3 | 35.2 | 30.0 | 30.0 |
| 2015-Q2 | 33.9 | 30.1 | 30.1 |
| 2015-Q1 | 31.7 | 30.0 | 30.0 |
| 2014-Q4 | 37.0 | 30.0 | 30.0 |
| 2014-Q3 | 37.5 | 32.1 | 29.9 |
| 2014-Q2 | 36.5 | 33.3 | 31.9 |
| 2014-Q1 | 38.4 | 35.3 | 30.3 |
| 2013-Q4 | 34.6 | 30.5 | 30.7 |
| 2013-Q3 | 33.7 | 30.5 | 30.2 |
| 2013-Q2 | 35.7 | 30.1 | 30.1 |
| 2013-Q1 | 35.8 | 30.0 | 30.7 |