Probability of Digits Appearing in a Selection of Numbers

There are 10 digits - 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 - and you might naively thinks that these numbers are equally likely to appear in any selection of numbers.
You are wring!
The British national lottery for example, picks 5 numbers from the numbers 1 to 49
In the numbers 1 to 49,
0 appears in 10, 20, 30, 40 - a total of 4 times.
1 appears in 1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 31, 41 - a total of 15 times.
2 appears in 2, 12, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 32, 42 - a total of 15 times.
3 appears in 3, 13, 23, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 43 - a total of 14 times.
4 appears in 4, 14, 24, 34, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 - a total of 15 times.
5 appears in 5, 15, 25, 35, 45 - a total of 5 times.
6 appears in 6, 16, 26, 36, 46 - a total of 5 times.
7 appears in 7, 17, 27, 37, 47 - a total of 5 times.
8 appears in 8, 18, 28, 38, 48 - a total of 5 times.,br / 9 appears in 9, 19, 29, 39, 49 - a total of 5 times.
1, 2, 3, 4 iare the digits most likely to appear an 0 is the least.