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| Number Range | Introduced | Builder | Engine | Seats | Withdrawn |
| --- | --- | --- | --- | --- | --- |
| 1 | 1934 | Park Royal | 1 AEC of hp (kW) | 69 | 1955 |
| 2–4 | 1934 | Park Royal | 2 AEC of hp (kW) | 44 | 1954–1958 |
| 5–7 | 1935 | Gloucester RCW | 2 AEC of hp (kW) | 70 | 1957–59 |
| 8–9, 13–16 | 1936 | Gloucester RCW | 2 AEC of hp (kW) | 70 | 1957–60 |
| 10–12 | 1936 | Gloucester RCW | 2 AEC of hp (kW) | 63 | 1956–57 |
| 17 | 1936 | Gloucester RCW | 2 AEC of hp (kW) | None | 1959 |
| 18 | 1937 | Gloucester RCW | 2 AEC of hp (kW) | 49 | 1957 |
| 19–33 | 1940–41 | GWR, Swindon | 2 AEC of hp (kW) | 48 | 1960–62 |
| 34 | 1941 | GWR, Swindon | 2 AEC of hp (kW) | None | 1960 |
| 35–38 | 1941–42 | GWR, Swindon | 2 AEC of hp (kW) | 60 + 44 | 1957, 1962 |
Question:
What is the number range for the Gloucester RCW builder introduced in 1937?
Answer:
18.0