A new trial is a reexamination in the same court of an issue of fact after a verdict by a jury, report of a referee, or a trial and decision by the court. The former verdict, report, or decision shall be vacated and a new trial granted on the application of the party aggrieved for any of the following causes affecting materially the substantial rights of such party: (1) Irregularity in the proceedings of the court, jury, referee, or prevailing party or any order of the court or referee or abuse of discretion by which the party was prevented from having a fair trial; (2) misconduct of the jury or prevailing party; (3) accident or surprise, which ordinary prudence could not have guarded against; (4) excessive damages, appearing to have been given under the influence of passion or prejudice; (5) error in the assessment of the amount of recovery, whether too large or too small, if the action is upon a contract or for the injury or detention of property; (6) that the verdict, report, or decision is not sustained by sufficient evidence or is contrary to law; (7) newly discovered evidence, material for the party applying, which the moving party could not, with reasonable diligence, have discovered and produced at the trial; and (8) error of law occurring at the trial and excepted to by the party making the application.