Sold rental house. How to allocate the sales price & expenses between the land and asset?

Bought the house in 2014 and in that year when I did my taxes, I allocated the land value to be 26.6% of the sales price. On my most recent property tax bill the land value of the property was 37% of the net taxable value. Bought the house for $200,000, sold house for $400,000,did improvements of ~$70,000. The expenses involved in selling the house were $28,000. 

On TT Sales information page, how do I  "divide, or allocate the sales price & expenses between the land and asset" to determine "sales price, asset sales expense, land sales price, and land sales expense"?