10. 有 78 個數據依規則排列如下：$\frac{1}{1}, \frac{1}{2}, \frac{2}{2}, \frac{1}{3}, \frac{2}{3}, \frac{3}{3}, \frac{1}{4}, \frac{2}{4}, \frac{3}{4}, \frac{4}{4}, \dots, \frac{1}{12}, \frac{2}{12}, \dots, \frac{12}{12}$，則中位數為____。