The timing of insertion sort is not correct

I wrote a insertion sort method, fillArray() to fill an array with numbers from 0 to array.length in unsorted order. First, fill the array, then sort this array.Run 100 times, and sorted the timing needed to sort in another array. Finally, calculate the mean of these 100 timings. My result is round 5*10^6, but other's round 1.2*10^7. I could not figure out where is wrong. enter image description here enter image description here