计数只有特殊字符R的单元格

I have a data.frame as below. I would like to get a list of cells that dont have even a single number or a-to-z and their frequency. How could I do that? In case of below data I want a table. In the table's first column i will have * and . These second column will show frequency of those values (1 and 2 respectively). "a*" and "21.9" wont appear because they contain at least one number or a-zI have a data.frame as below. I would like to g