Where—
compensation shall be payable by the landlord to the tenant, in addition to any other compensation so payable apart from this section in respect of the holding.
The amount of compensation payable under this section shall be equal to the value of the additional benefit (if any) which would have accrued to the tenant if the tenancy had, instead of being terminated as provided by the notice, been terminated by it on the expiration of twelve months from the end of the year of tenancy current when the notice was given.
For the purposes of subsection (2) above, the current year of a tenancy for a term of two years or more is the year beginning with such day in the period of twelve months ending with the date on which the notice is served as corresponds to the day on which the term would expire by the effluxion of time.