| | | 1920 | | 1964 | 1974 | | | | | | | | | | | 900~1200kg 600~900kg | 46kg | 42kg | 270~340kg | 500kg 1.88kg | 60%~70% | 80%~85% 16 | 418kg 66.3% | 1700~1800kg 4.0%~4.7% | | | 13.7% | | | | | | | | | | | | | | |