Each district commissioner may serve a one-year term as vice-chair on the basis of a six-year rotation, the term beginning on the anniversary date of the seventh day next following the general election next preceding his or her term each year in the following order: District 1, District 3, District 6, District 5, District 4, District 2. A commissioner may elect to pass at any time that the term of the vice-chair arises or may swap terms with another consenting commissioner. The vice-chair, when presiding in the absence of the chair, shall have a vote in all matters before the commission except in the event of a tie whereupon the vice-chair, when presiding, shall have a second vote for the limited purpose of casting the deciding vote. The vice-chair, during his or her term as vice-chair, shall receive a salary supplement of five thousand dollars ($5,000) per year. In addition to his or her duties of presiding in the absence of the chair, the vice-chair will be expected to perform additional duties as assigned by the chair.