288.121.  Rate increased when average balance in fund is less than certain amount, how — rate calculations for certain years. — On October first of each calendar year, if the average balance, less any federal advances, of the unemployment compensation trust fund of the four preceding quarters (September thirtieth, June thirtieth, March thirty-first and December thirty-first of the preceding calendar year) is less than four hundred fifty million dollars, then each employer's contribution rate calculated for the four calendar quarters of the succeeding calendar year shall be increased by the percentage determined from the following table:

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For calendar years 2005, 2006, and 2007, the contribution rate of any employer who is paying the maximum contribution rate shall be increased by forty percent, instead of thirty percent as previously indicated in the table in this section.