Tier 5 extension - how long?

Hi,

I have applied for a Tier 5 extension (Government Exchange) about 5 weeks ago, and completed my biometrics 3 1/2 weeks ago. Any ideas on how much longer it will be for me to get my visa extension? I know the SLA is 8 weeks, but was told it takes less time... What is your experience? And why is it that the UK BA does not publish data telling you of timings, when all the other consulates tell you exactly how many applications are processed in the first 2 days/3 days etc?

Regards

T