2023 North Dakota Code 57-02.2-02 – Improvement defined

2022 North Dakota Code 57-02.2-02 – Improvement defined

2021 North Dakota Code 57-02.2-02 – Improvement defined

2019 North Dakota Code 57-02.2-02 – Improvement defined

2016 North Dakota Code 57-02.2-02 – Improvement defined

2014 North Dakota Code 57-02.2-02 – Improvement defined

2009 North Dakota Code 57-02.2-02 – Improvement defined