Iowa Code § 261.12
83 Acts, ch 197, §13; 84 Acts, ch 1302, §16; 85 Acts, ch 263, §16; 88 Acts, ch 1284, §27; 89 Acts, ch 300, §3; 89 Acts, ch 319, §43; 90 Acts, ch 1253, §122; 90 Acts, ch 1272, §49; 91 Acts, ch 10, §1; 91 Acts, ch 258, §39; 95 Acts, ch 218, §21; 96 Acts, ch 1215, §36; 96 Acts, ch 1219, §4, 5; 97 Acts, ch 212, §25; 98 Acts, ch 1215, §33; 99 Acts, ch 205, §28; 2000 Acts, ch 1223, §26