A credit union organized under this chapter, its property, franchises, capital, reserves, surpluses, and other funds, and its income are exempt from taxation by the state or a political subdivision of the state, except that real property and tangible personal property owned by a credit union is subject to taxation to the same extent that similar property is taxed. This section does not prevent holdings in a credit union organized under this chapter from being included in the valuation of the personal property of the owners or holders under taxes imposed by the state or a political subdivision of the state.