Kammala wannan jumla: Stamper ya kasance mai lambar tagulla a gasar
Gasar Zakarun Taekwondo ta Duniya ta 2011. Ya kuma yi gasa a wasannin Olympics na bazara na 2012 kuma ya kai wasan kusa da na karshe. Ya yi rashin nasara a wasan lambar tagulla da Rohullah Nikpai na Afghanistan, ya ƙare a matsayi na 5.