Until end-1998, affirmation of the reference rate was based on a law (284/1995) enacted 3 March 1995, which amended the Interest Rates Act (633/1982); and the Bank of Finland, in practice, set the rate. Under another law (997/1998) amending the Interest Rates Act, the Ministry of Finance has since then affirmed the reference rate. The Interest Rates Act was amended, effective 1 July 2002 (340/2002), so that the responsibility for announcing the rate was transferred back to the Bank of Finland. On the basis of the revised law, the reference rate (column 1) is the same as the interest rate applied on the last main refinancing operation of the ECB prior to the first calendar day of the half-year in question, rounded up to the nearest one-half percentage point. The affirmed reference rate is then effective for the next six months. The penalty interest rate given in the table (column 3) is the penalty interest rate referred to in section 4, subsection 3 of the Act. Due to an amendment to the Interest Rates Act effectives (340/2002) as from 16 March 2013, the Bank of Finland also announces another penalty interest rate applicable to commercial contracts. The penalty interest rate given in the table (column 5) is the penalty interest rate referred to in section 4 a of the Act.