(1) In the absence of any agreement to the contrary, the rent of the premises let out after the commencement of this Act shall be liable to be increased at the rate of 5 % per annum and the amount of increase of rent shall be merged in such rent after ten years. Such rent shall further be liable to be increased at the similar rate and merged in similar manner till the tenancy subsists.
(2) Any agreement for increase of rent in excess of 5% per annum shall be void to that extent.