▁founder ▁of ▁Microsoft , ▁added ▁$ 9 ▁billion ▁to ▁his ▁fortune ▁since ▁ 2 0 1 3 ▁and ▁to pped ▁the ▁ 2 0 1 4 ▁billion aire ▁list . ▁ ▁He ▁has ▁to pped ▁the ▁list ▁ 1 5 ▁of ▁the ▁previous ▁ 2 0 ▁years , ▁but ▁was ▁last ▁number ▁one ▁in ▁ 2 0 0 9 . ▁ ▁Mexican ▁ty co on ▁Carlos ▁S lim ▁came ▁in ▁second ▁place ▁after ▁being ▁number ▁one ▁the ▁previous ▁four ▁years . ▁Z ara ▁founder ▁A man cio ▁Or te ga ▁placed ▁third ▁for ▁the ▁second ▁consecutive ▁year . ▁American ▁invest or ▁Warren ▁Buff ett ▁was ▁in ▁the ▁top ▁five ▁for ▁the ▁ 2 0 th ▁consecutive ▁year , ▁placing ▁fourth . ▁Oracle ▁founder ▁Larry ▁Ell ison ▁rounded ▁out ▁the ▁top ▁five . ▁ ▁America ' s ▁Christ y ▁Wal ton ▁was ▁the ▁highest ▁ranking ▁female , ▁placing ▁nin th ▁overall . ▁ ▁Ali ko ▁D ang ote ▁of ▁Niger ia ▁became ▁the ▁first ▁African ▁ever ▁to ▁crack ▁the ▁top ▁ 2 5 , ▁with ▁an ▁estimated ▁net ▁worth ▁of ▁$ 2 5 ▁billion . ▁ 2 4 - year - old ▁Per en na ▁Ke i , ▁daughter ▁of ▁Chinese ▁real ▁estate ▁developer ▁Ji ▁Ha ip eng , ▁was ▁the ▁young est ▁person ▁on ▁the ▁list . ▁ ▁At ▁age ▁ 9 9 , ▁David ▁Rock ef eller ▁was ▁the ▁oldest . ▁ ▁Among ▁the ▁largest ▁gain ers ▁from ▁the ▁previous ▁year ' s ▁list ▁was ▁Facebook ▁founder ▁Mark ▁Z ucker berg .