Exactly, the numbers stated are meaningless, nothing new from the nbn there.
It might be... 85% of connections capable of up to 100mbs are connected at the top tier.
It could be the overall number of 100mbps connections has increased, with the percentage of the total falling due to recent FTTN additions which are incapable of that speed.
That's before addressing questions of the backhaul provisioned being capable of making the tiers actually usable.
Just more useless statistics, there's not enough information given to mean anything at all.