Generally these articles use 1990 as a frame of reference. To be fair based on the initial graph shown alone, the UK has almost reached 50% of 1990 values also, though perhaps other countries have already achieved 50% of 1970 values.
Generally these articles use 1990 as a frame of reference. To be fair based on the initial graph shown alone, the UK has almost reached 50% of 1990 values also, though perhaps other countries have already achieved 50% of 1970 values.