The following percentages of the data fall within the given numbers of standard deviation:
[tex]\begin{gathered} 1\sigma\rightarrow68\text{ percent} \\ 2\sigma\rightarrow95.5\text{ percent} \\ 3\sigma\rightarrow99.7\text{ percent} \end{gathered}[/tex]
Therefore, 68% of the data will fall within one standard deviation.
