service tax exemption

any one can help me about the service tax exemption of Rs.10 lacs.

• The limit Rs.10 lacs is count for every year that means service tax is collectable once the billing is exceeds Rs.10 lacs and the service tax is to be collected from Rs.10 lacs and above in each financial year , OR

• Once billing is exceeds Rs.10 lacs in a year and for immediate  subsequent year liable to collect service tax irrespective of the crossing the billing of Rs.10 lacs form Rs.1 on wards.

pls. clarify