T1135 -- maximum cost / cost amount end of the year

Hi Guys

I have RSU granted by my previous employer. Stocks are in E - trade account US.

I am trying to fill the t1135 form

What value to input in maximum cost — Is this the total highest value of my stocks in the year
In case of cost amount end of year – value of stocks on Dec 31 for that particular year.

I also read somewhere that maximum cost should be zero, as I did not purchase these stocks, also read somewhere that it should be the total value, the day I immigrated ?

Thanks