To accurately answer your question regarding which imports have increased over the past 6 years (coal, oil, lumber), I would need up-to-date statistics or data on import trends in those commodities. However, I don't have real-time data access.
As of my last update in October 2023, trends in commodities like coal, oil, and lumber can vary based on economic conditions, regulatory changes, and shifts in market demand.
If you have access to specific trade reports or economic data for the past 6 years, you could check those sources to determine the right answer. If no specific data is available, I cannot provide a definitive answer from the options given.
If you are looking for general trends to make an educated guess, you might consider that:
- Coal imports have seen fluctuations due to environmental regulations and reduced demand in some regions.
- Oil imports tend to fluctuate based on geopolitical situations and domestic production levels.
- Lumber imports can vary significantly, especially in response to housing market demands.
Without specific data, I recommend consulting recent trade statistics or economic reports to ascertain the accurate trend.