I meant it has been happening since the EU-wide regulation came out. London reaches the critical yearly level at the first weeks of January and only cosmetic changes have been applied. E.g. a 20-year-old, rusty diesel truck, that makes ~£500/day gets away with £12.5 fee instead of ban from Greater London. The actual polluters won't invest in newer vehicles, because the lease is more expensive than just £12.5 per day.