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:
| Year | Builder | Motors | Trailers | Control Trailers |
| --- | --- | --- | --- | --- |
| 1923 | BRCW | — | 1 | — |
| 1923 | CLCo | — | 1 | — |
| 1923 | GRCW | — | 1 | 1 |
| 1923 | Leeds | — | 1 | — |
| 1923 | MCWF | — | 1 | — |
| 1923 | BRCW | — | 35 | — |
| 1923 | CLCo | 41 | 40 | — |
| 1923 | MCWF | 40 | — | 35 |
| 1924 | BRCW | — | 50 | — |
| 1924 | CLCo | — | — | 25 |
| 1924 | MCWF | 52 | — | — |
| 1925 | CLCo | 48 | — | — |
| 1925 | MCWF | — | 5 | 67 |
| 1926 | MCWF | 64 | 48 | — |
| 1927 | MCWF | 110 | 160 | 36 |
| 1927 | UCC | 77 | 37 | 68 |
| 1929 | UCC | 18 | 17 | 18 |
| 1930 | MCCW | 22 | 20 | 20 |
| 1930 | UCC | 2 | 4 | — |
| 1931 | BRCW | — | 90 | — |
| 1931 | GRCW | — | 40 | — |
| 1931 | MCCW | 145 | — | — |
| 1934 | MCCW | 26 | — | — |
| Totals | 1,466 | 645 | 551 | 270 |
Question:
I want the control trailers for 1931 with builder of grcw
Answer:
—