Error with get_case()

import sqlite3

class Storage:
    connection = sqlite3.connect('./storage.db')
    cursor = connection.cursor()
    bounds = [0, 50, 100, 250, 500, 1000, 2500, 5000, 10000, 25000, 50000, 100000, 250000, 500000, 1000000]

    def __init__(self):
        Storage.cursor.execute( ''' CREATE TABLE Levels(Member TEXT PRIMARY KEY, XP TEXT) ''' )
        Storage.cursor.execute( ''' CREATE TABLE Modmail(Docket TEXT PRIMARY KEY, Report TEXT) ''' )
        Storage.connection.commit()

    def get_level(self, xp: int):
        for level in range(len(Storage.bounds)):
            if xp < Storage.bounds[level+1] and xp >= Storage.bounds[level]:
                return level+1
            else:
                pass

    def get_xp(self, cls, memberID: str):
        results = Storage.cursor.execute( ''' SELECT XP FROM Levels WHERE Member = ? ''', (memberID) )
        return result[0]

    def add_xp(self, cls, memberID: str, gain: int):
        current = Storage.cursor.execute( ''' SELECT XP FROM Levels WHERE Member = ? ''', (memberID) )
        new = int(current) + gain
        Storage.cursor.execute( ''' UPDATE Levels SET XP = ? WHERE Member = ? ''', (new, memberID) )
        Storage.connection.commit()

    def new_case(docket: str, report: str):
        Storage.cursor.execute( ''' INSERT INTO Modmail(Docket, Report) VALUES (?, ?) ''', (docket, report) )
        Storage.connection.commit()

    def get_case(param: str):
        results = {}
        search = Storage.cursor.execute( '''SELECT Report FROM Modmail WHERE Docket LIKE '%?%' ''', (param) )
        for report in search:
            results[report] = cursor.execute( '''SELECT Docket FROM Modmail WHERE Report = ?''', (report) )
        return results

Storage.get_case("35434")