# 数据来源

- WITS / World Bank, China exports of HS 847431 Concrete or mortar mixers by partner, 2024: https://wits.worldbank.org/trade/comtrade/en/country/CHN/year/2024/tradeflow/Exports/partner/ALL/product/847431
- WITS page refreshed by source; access date: 2026-06-25
- World Bank indicator `gdp_current_usd` / GDP (current US$), latest non-null year 2024: https://api.worldbank.org/v2/country/KAZ/indicator/NY.GDP.MKTP.CD?format=json&per_page=20
- World Bank indicator `gdp_growth_pct` / GDP growth (annual %), latest non-null year 2024: https://api.worldbank.org/v2/country/KAZ/indicator/NY.GDP.MKTP.KD.ZG?format=json&per_page=20
- World Bank indicator `population` / Population, total, latest non-null year 2024: https://api.worldbank.org/v2/country/KAZ/indicator/SP.POP.TOTL?format=json&per_page=20
- World Bank indicator `urban_population_pct` / Urban population (% of total population), latest non-null year 2024: https://api.worldbank.org/v2/country/KAZ/indicator/SP.URB.TOTL.IN.ZS?format=json&per_page=20
- World Bank indicator `gross_fixed_capital_formation_pct_gdp` / Gross fixed capital formation (% of GDP), latest non-null year 2024: https://api.worldbank.org/v2/country/KAZ/indicator/NE.GDI.FTOT.ZS?format=json&per_page=20
- World Bank indicator `exchange_rate_lcu_per_usd` / Official exchange rate (LCU per US$, period average), latest non-null year 2024: https://api.worldbank.org/v2/country/KAZ/indicator/PA.NUS.FCRF?format=json&per_page=20

## 估算说明
- 混凝土售价、生产成本、人工成本、投资预算、ROI、回本周期为参数化估算，不是官方统计。
- 估算值用于询盘前初筛；正式报价需要按设备配置、港口、汇率、税费、原材料和当地施工条件重新计算。