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:
| Class | Wheel arrangement | Manufacturer | Year made | Quantity made | Quantity preserved | Year(s) withdrawn | Comments |
| --- | --- | --- | --- | --- | --- | --- | --- |
| William George Beattie (1871–1878) | William George Beattie (1871–1878) | William George Beattie (1871–1878) | William George Beattie (1871–1878) | William George Beattie (1871–1878) | William George Beattie (1871–1878) | William George Beattie (1871–1878) | William George Beattie (1871–1878) |
| 282 | 0-6-0 | Beyer, Peacock & Co. | 1873–1880 | 8 | 0 | 1905–1913 | "Ilfracombe Goods" |
| 302 | 0-6-0 | Beyer, Peacock & Co. | 1874–1878 | 35 | 0 | 1889–1925 | Single framed Goods |
| 318 | 4-4-0T | Beyer, Peacock & Co. | 1875 | 6 | 0 | 1906–1913 | "Plymouth Tank" |
| 330 | 0-6-0ST | Beyer, Peacock & Co. | 1876–1882 | 20 | 0 | 1924–1933 | "Saddleback" |
| 348 | 4-4-0 | Beyer, Peacock & Co. | 1877 | 20 | 0 | 1889–1905 | "Jumbo" |
Question:
How many have a class of 330?
Answer:
20.0