This is based on our Feb 2020 advertisement,
Average download speed during busy hours is 86.6% of plan speed and 79.9% of plan speed during busiest hour. Average upload speed during busy hours is 87.4% of plan speed.
If your plan is 100/40 then during busy hour: 86.6/34.96 Mbps and during busiest hour: 79.9/34.96 Mbps.
I hope above information can help.