(1) Less than 4 years 24 age 49 2.1% (2) At least 4 years but less than 6 years 23 age 48 2.2% (3) At least 6 years but less than 8 years 22 age 47 2.3% (4) At least 8 years but less than 10 years 21 age 46 2.4%
Source. 1967, 134:1; 405:4. 1973, 449:1, 2; 524:1. 1974, 33:1. 1975, 435:1. 1977, 510:2. 1979, 297:1, 2; 420:3, 4. 1981, 568:162. 1983, 223:1; 322:2. 1986, 95:2. 1987, 248:1; 362:1; 394:1, 2. 1988, 193:1, 10. 1991, 313:3. 1992, 112:1. 2000, 120:2, 6. 2011, 224:166, eff. July 1, 2011.