Collection Fund Accounting 2016/17 - NNDR share split changes

I would be grateful if anyone can confirm their position on this...

I am completing the NNDR 2016/17 accounting entry to split the shares for GLA and CLG. Normally the split has been 20% GLA and 50% CLG. However, with 2017/18 share changes (GLA 37% and CLG 33%), should the debtors/creditors, etc be split using 2017/18 for the 2016/17 account - just like the Council tax balances we use next year's demand/precept ratios.

I think CIPFA guidance would suggest to use 2017/18 shares, but then the NNDR3 16-17 split is using 16/17 share percentages - which I assume GLA and CLG use to account in their books.

If 2017/18 share percentage is used then would it not create an inconsistent reporting between L.A, GLA and CLG? Importantly what's the correct ratios we should use?

Many thanks for your help.