Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| number | symbol | name | 21st | 22nd | 23rd | 24th | 25th | 26th | 27th | 28th | 29th | 30th |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 21 | Sc | scandium | 582163 |  |  |  |  |  |  |  |  |  |
| 22 | Ti | titanium | 602930 | 639294 |  |  |  |  |  |  |  |  |
| 23 | V | vanadium | 151440 | 661050 | 699144 |  |  |  |  |  |  |  |
| 24 | Cr | chromium | 157700 | 166090 | 721870 | 761733 |  |  |  |  |  |  |
| 25 | Mn | manganese | 158600 | 172500 | 181380 | 785450 | 827067 |  |  |  |  |  |
| 26 | Fe | iron | 163000 | 173600 | 188100 | 195200 | 851800 | 895161 |  |  |  |  |
| 27 | Co | cobalt | 167400 | 178100 | 189300 | 204500 | 214100 | 920870 | 966023 |  |  |  |
| 28 | Ni | nickel | 169400 | 182700 | 194000 | 205600 | 221400 | 231490 | 992718 | 1039668 |  |  |
| 29 | Cu | copper | 174100 | 184900 | 198800 | 210500 | 222700 | 239100 | 249660 | 1067358 | 1116105 |  |
| 30 | Zn | zinc | 179100 |  |  |  |  |  |  |  |  |  |
| 36 | Kr | krypton | 85300 | 90400 | 96300 | 101400 | 111100 | 116290 | 282500 | 296200 | 311400 | 326200 |
| 42 | Mo | molybdenum | 87000 | 93400 | 98420 | 104400 | 121900 | 127700 | 133800 | 139800 | 148100 | 154500 |
Question:
what is the number of symbol zn?
Answer:
30