如何获得动态的最大行数？

I want to get the top #nr_of_rows - (int)(#nr_of_rows / 10 - 1) of a table. So like if you have 63 rows, it would return 3 rows, 90 rows would return 10, 85 would return 5, etc.. Of course this can be done in two queries, just wondering if it can be done in one query.I want to get the top #nr_of_rows - (int)(#nr_o