We can do this by the long, slow process of counting ...
From 0 through 99 it appears 19 times:
3, 13, 23, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 43, 53, 63, 73, 83, 93
From 100 through 199, it appears another 19 times, for a total of 38 times.
From 200 through 299, it appears another 19 times, for a total of 57 times.
From 300 through 309, it appears another 11 times, for a total of 68 times:
300, 301, 302, 303, 304, 305, 306, 307, 308, 309
From 310 through 319, it appears another 11 times, for a total of 79 times.
Then there are 320, 321, 322, 323, 324, 325, 326 for another 8 times, for a total of 87 times.