If you sum the occurrences of numbers 1-6, you get 1051 + 1012 + 1042 + 983 + 1015 + 1042 = 6145. The expected count (if the numbers were uniformly random) is

If you sum the occurrences of numbers 1-6, you get 1051 + 1012 + 1042 + 983 + 1015 + 1042 = 6145. The expected count (if the numbers were uniformly random) is only 6000, on average. If you repeat your experiment, you will find that this sum is greater than 6000 more often than not.