In a private corporation, any individual who is included within the meaning of “employee” pursuant to subdivision (a) of Section 621 and who is the sole shareholder, or the only shareholder other than his or her spouse, may file a statement electing to be excluded from disability insurance coverage for benefits and contributions under this division. The election shall be effective on the first day of the calendar quarter in which the statement is filed. The election shall be effective during the remainder, if any, of the calendar year in which the statement is filed and not less than the two succeeding complete calendar years, and in all subsequent calendar quarters while the statement is in effect.