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:
| Card | Weight Class | Round | Time | Method |
| --- | --- | --- | --- | --- |
| Preliminary | Welterweight | 3.0 | 5:00 | Decision (split) |
| Preliminary | Light Heavyweight | 3.0 | 5:00 | Decision (split) |
| Preliminary | Lightweight | 3.0 | 5:00 | Decision (unanimous) |
| Preliminary | Welterweight | 3.0 | 5:00 | Decision (unanimous) |
| Main | Lightweight | 3.0 | 5:00 | Decision (split) |
| Main | Welterweight | 3.0 | 5:00 | No Contest |
| Main | Light Heavyweight | 3.0 | 5:00 | Decision (unanimous) |
| Main | Light Heavyweight | 1.0 | 4:59 | KO (punch) |
| Main | Welterweight | 4.0 | 5:00 | TKO (doctor stoppage) |
Question:
What is the smallest round for the welterweight class with a preliminary card?
Answer:
3.0