Hi - This isnt a detailed report, just a 'quick' half hour analysis.
SNRm is usually what we look at first as it gives a good indication how your line performs over the course of the day.
Looking at your data over the past few days, there appears to be some sort of pattern emerging. -
Your line is perfectly fine between the hours of circa 7am and 5.30 pm. Things start to go downhill a bit afer 6pm and are at their worst at around 9:30.
Next I looked at your cumulative Err/Secs. Those seem to show a fairly steady growth throughout the day, perhaps a bit steeper after 6pm especially on the 4th, but nothing too dramatic.
Your attenuation shows that you are apprx 2.7km from the exchange and if all was perfect then you should be looking at a max sync of around 10.6 Mbps
From your bit loading - Indicates this is an adsl/2+ line - I see some nasty spots - more on this later.
Your hlog looks good - No bridge taps in the wiring. Actually looks good for a longish line and a lovely smooth decline over distance, suggesting no obvious problems in the physical wiring.
QLN - hmmm, some nice spiking :/ More on this later because I could practically overlay this with your bit loading.
QLN indicates crosstalk - or in somecases EMI. From the bit loading, your line is noisy in places I wouldnt expect to see unless there is some sort of interference. My gut reaction is saying EMI - coupled with your SNRm its something that is only switched on after 5:30 at night and turned off at 7am in the morning. QLN is a snapshot in time and can only be taken during sync, your last sync would be just entering the noisy period. It would be interesting to see a QLN taken during 9-5 on a working day but no matter, I think I have sufficient to go off to show the problematic areas. Noise at those particular tones are what is causing low bit loading at certain frequencies, which is why you arent quite capable of attaining your max speed. The round bumps at 700 -1200 kHz onwards also to me suggest EMI.
EMI/REIN is very hard to track down, but IMHO there is something there causing this which notably gets worse outside of working hours. I have no idea what is causing it, but 'something' is definitely there. Because of the timing then getting BT to do something about it is going to be exceedingly difficult, because it looks line your line is ok during 9-5 and any tests they run during these hours will likely show good.
If it was me Id be racking my brains to find out if anything gets switched on during the mentioned hours. Street lighting, central heating, PIR lighting, faulty monitors, the list is practically endless. I'd also check the frequencies against
here to make sure its not a local transmitter or radio HAM. Sorry its got late and Im too tired atm to zoom in on any actual tones to check against any possible local radio stations (aside from the fact I dont know your location).