ESIC limit - unit has less than 20 employees under the salary bracket of 21000

Dear All, I had a query for ESIC limit, what is the minimum no of employees required to start ESIC deduction. Eg If a unit has less than 20 employees under the salary bracket of 21000 as per new rule should we start ESIC deduction for for them, or less than 20 employees are expented.
Regards,
Prashant

1. Min no of emp required: For Pune Region Maharashtra: " applies to all non-seasonal factories/ establishment employing 10/20 or more persons again establishments employing 20 or more persons for wages and falling within the scope of an implemented geographical area.
As of now, employees of factories/ establishments, that fall within the ambit of coverage, and earning wages not exceeding Rs. 21,000/- per month are covered under the ESI Scheme."
2. Nature of Business: other than prev inclusion has been extended to
i. Shops
ii. Hotels & Restaurants, Clubs
iii. Cinemas, including preview theatres
iv. Newspaper establishments
v. Road Motor Transport establishments
3. Coverage as on number:
i. Voluntary contribution may be done even if 1 emp is there
ii. Establishment(not factory), If total emp = 25( or 20 or 21) and emp with wages <= 21000 are 19( or 18 or 15) - it will still fall under esic coverage

for applicability of the act the salary below or above 21000 is not criteria, total no of employees are counted for applicability, if it exceeds TEN for units where power is used otherwise TWENTY
however contribution is payable for the employees who draw gross wages below 21001/-

in our company all the employees salary is more than Rs 21000/- is it necessary to register ESI??? we 25 members