Chii chinonzi nguva yechibvumirano?
Nguva inguva-yakakosheswa kuyerwa kweavhareji yemari inoyerera yechinhu chemari chinobhadhara mubereko. Vashambadziri vezvisungo vanoshandisa nguva yekuyera kunzwisisika kwemari yemari yechinhu. Rudzi rwenguva yekuverenga runosanganisira Macaulay, Modified uye Effective durations.