Backdated special levy for 'hotel' use

Hi, just after some basic advice regarding special levy liability in Victoria…
I bought an apartment (in Victoria) in 2016 as an investment. My lot is leased to a hotel, along with about 50% of the other units in the complex.
Late in 2018, the OC engaged an accountant to review the liability of each lot owner with respect to proportioning additional wear & tear costs to certain apartments due to commercial (hotel) use.
The accountant researched & estimated the total additional cost of wear & tear, maintenance, electricity etc and proportioned this across those lots leased to the hotel. The costs go back over the full 8 year period to 2012 and have been attributed and invoiced to each affected lot owner.
The outcome of this review is that I have been issued an invoice from the body corporate for ‘special levy’ which dates back approx 8 years to 2012. This well predates my ownership / interest in this apartment.
I did due diligence prior to purchase and there was no sign of this additional liability at settlement…
My question is, am I liable for the full fee for the 8 years, or a pro-rata amount (e.g. 3/8 of the total fee)?
Doesn’t seem fair to be liable for charges which pre-date ownership…