年代 | GB/T | ГOST | 相对误差/% |
2011 | 19.00 | 18.20 | −4.12 |
2012 | 19.00 | 22.70 | 19.47 |
2013 | 19.80 | 22.80 | 15.15 |
2014 | 21.10 | 26.50 | 26.60 |
2015 | 21.80 | 24.80 | 17.76 |
2016 | 21.5 | 23.5 | 9.30 |
2017 | 19.6 | 23.5 | 19.89 |