N'ime usoro ego a maara dị ka ọkọlọtọ ọla edo, a na-enye ụfọdụ ịdị arọ nke ọla edo aha nke otu ego. Ruo ogologo oge, gọọmentị United States setịpụrụ uru nke US dollar ka otu troy ounce hà $ 20.67 ($ 0.665 kwa gram), mana na 1934 dollar dara na $ 35.00 kwa troy ounce ($ 0.889/g). Site na 1961, ọ na-esi ike ịnọgide na-akwụ ụgwọ a, na ọdọ mmiri nke US na European ụlọ akụ kwetara iji dozie ahịa iji gbochie nkwụsịtụ ọzọ megide ịrị elu nke ọla edo. Na March 17, 1968, ọnọdụ akụ na ụba mere ka ọdịda nke ọla edo, na usoro nkwụnye ego abụọ na-adabere na ya bụ ebe a ka na-eji aha nke otu ego ego.
ọlaedo