ESIC Payment if Employee reduced to below minimum

Dear Friends,

My Co. had more than 20 employees drawing wages under 15K in 2014- 2015 however, after few months all employees were relieved of duty and persons drawing wages less than 15K fell below the statutory minimum as required under ESIC.

is still the employer required to pay ESIC during the year 2014- 15 or in later years after workers fall before statutory minimum??

kindly revert....