290.550.  Definitions. — As used in sections 290.550 to 290.580, the following terms mean:

  (1)  "Laborers from nonrestrictive states", persons who are residents of a state which has not enacted state laws restricting Missouri laborers from working on public works projects in that state, as determined by the labor and industrial relations commission;

  (2)  "Missouri laborer", any person who has resided in Missouri for at least thirty days and intends to become or remain a Missouri resident;

  (3)  "A period of excessive unemployment", any month immediately following two consecutive calendar months during which the level of unemployment in the state has exceeded five percent as measured by the United States Bureau of Labor Statistics in its monthly publication of employment and unemployment figures;

  (4)  "Public works", projects defined as public works pursuant to section 290.210.