data
| Date | L，LF日 | L，LF晚 | L，LF夜 |
|---|---|---|---|
| dB | dB | dB | |
| 2021-Q4 | 30.8 | 25.8 | 21.5 |
| 2021-Q3 | 28.7 | 24.0 | 22.5 |
| 2021-Q2 | 31.6 | 26.8 | 23.7 |
| 2021-Q1 | 29.1 | 23.4 | 21.5 |
| 2020-Q4 | 32.4 | 28.0 | 24.2 |
| 2020-Q3 | 30.5 | 27.4 | 26.0 |
| 2020-Q2 | 30.3 | 25.1 | 22.4 |
| 2020-Q1 | 30.1 | 22.9 | 21.8 |
| 2019-Q4 | 31.3 | 27.5 | 22.8 |
| 2019-Q3 | 30.1 | 25.5 | 24.1 |
| 2019-Q2 | 32.7 | 29.8 | 32.3 |
| 2019-Q1 | 32.3 | 28.7 | 26.1 |
| 2018-Q4 | 32.0 | 26.9 | 25.3 |
| 2018-Q3 | 33.4 | 25.0 | 25.4 |
| 2018-Q2 | 37.7 | 41.1 | 32.3 |
| 2018-Q1 | 38.6 | 31.9 | 29.1 |
| 2017-Q4 | 37.7 | 36.8 | 32.6 |
| 2017-Q3 | 37.6 | 33.6 | 31.3 |
| 2017-Q2 | 29.2 | 25.0 | 25.0 |
| 2017-Q1 | 30.5 | 25.1 | 25.0 |
| 2016-Q4 | 38.5 | 35.8 | 30.4 |
| 2016-Q3 | 38.4 | 34.6 | 31.9 |
| 2016-Q2 | 29.8 | 26.4 | 25.8 |
| 2016-Q1 | 31.5 | 30 | 30.2 |
| 2015-Q4 | 30.6 | 31.7 | 30.5 |
| 2015-Q3 | 33.1 | 30.0 | 30.0 |
| 2015-Q2 | 39.3 | 32.3 | 33.8 |
| 2015-Q1 | 36.2 | 30.3 | 30.1 |
| 2014-Q4 | 47.6 | 36.2 | 33.5 |
| 2014-Q3 | 48.0 | 35.4 | 32.8 |
| 2014-Q2 | 46.8 | 36.9 | 34.0 |
| 2014-Q1 | 45.6 | 37.0 | 35.1 |
| 2013-Q4 | 40.8 | 34.9 | 34.5 |
| 2013-Q3 | 40.5 | 34.1 | 34.9 |
| 2013-Q2 | 40.6 | 34.0 | 32.2 |
| 2013-Q1 | 38.1 | 35.0 | 34.2 |