Baki daya ana iya cewa mutane a fadin duniya sukan rayu rayuwa mai tsawo a doron kasa, tun wucewar karni na ashirin 20. A karni na ashirin da daya 21, mutane da dama a wasu kasashe sukan fi wasu mutane dadewa a doron kasa, a wasu kasashen a fadin duniya.
Hakan kuma yana da alaka da ingantattun tsarin kiwon lafiya, harkar noma na zamani, da tsare-tsare wajen sarrafa abubuwan da mutane keci, haka da zaman takewa mai nagarta. Wani bincike da ya bayyanar da kasashe da mutane sukafi dadewa a duniya sune.
Kasar Monaco, itace kasa ta farko da aka kiyasta mutane su kafi dadewa a duniya, inda mutane kan kai shekaru 89, sai kasar Hong Kong, mutane kan kai 84 kamun mutuwa, haka kasashen Switzerland, San Marino, Singapore, Japan, Italy, Spain, suma mutane kan kai shekaru 83.