Here's why:
* Data Collection Varies: Different organizations collect data on natural gas vehicles (NGVs) with varying methods and definitions.
* Global Differences: The popularity of NGVs varies significantly by country and region.
* Changing Trends: The number of NGVs is constantly changing due to factors like new car production, government incentives, and fuel price fluctuations.
To get the most up-to-date information, I recommend checking these sources:
* International Energy Agency (IEA): The IEA provides global energy data, including information on alternative fuels.
* National Associations: Look for national or regional associations for the natural gas vehicle industry.
* Government Agencies: Check with transportation agencies in your country or region for statistics on NGVs.
Please note that the data you find will likely be estimations or trends rather than precise counts.
