As stipulated by the Deposit Insurance Act, the assessment rate for deposit insurance shall be proposed by CDIC and approved by the competent authority prior to implementation. The deposit insurance assessment base shall be computed on total eligible deposits on the basis of the standard dates. The deposit insurance assessment rate in the R.O.C. is calculated using a risk-based assessment rate system, with the insured institutions' "Capital Adequacy Ratio" and the "Composite Score of the Risk-based Premium Rating System." At present, assessment rates are based on five different levels of risk: (1) For domestic banks and local branches of foreign and mainland Chinese banks , they are 0.05%, 0.06%, 0.08%, 0.11%, and 0.15% of the covered deposits, and the flat premium rate for eligible deposits in excess of coverage limit is 0.005%. (2) For credit cooperatives, they are 0.04%,0.05%,0.07%,0.10% and 0.14% of the covered deposits, and the flat premium rate for eligible deposits in excess of coverage limit is 0.005%. (3) For credit departments of farmers' and fishermen's associations, they are 0.02%, 0.03%, 0.04%, 0.05%, and 0.06% of covered deposits, and the flat premium rate for eligible deposits in excess of coverage limit is 0.0025%. Assessments are due in advance for each six-month period. The assessment base is computed once every semi-annual period. The standard dates for computing such a base are June 30 and December 31, and may be altered from time to time by CDIC.