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:
| Tie no | Home team | Score | Away team | Date |
| --- | --- | --- | --- | --- |
| 1 | Chesterfield | 2–0 | Barnsley | 9 December 1967 |
| 2 | Bournemouth & Boscombe Athletic | 2–0 | Northampton Town | 9 December 1967 |
| 3 | Barrow | 2–0 | Oldham Athletic | 9 December 1967 |
| 4 | Grantham | 1–3 | Altrincham | 9 December 1967 |
| 5 | Weymouth | 0–2 | Orient | 9 December 1967 |
| 6 | Yeovil Town | 1–3 | Margate | 13 December 1967 |
| 7 | Reading | 6–2 | Aldershot | 13 December 1967 |
| 8 | Grimsby Town | 1–1 | Bradford Park Avenue | 9 December 1967 |
| Replay | Bradford Park Avenue | 4–1 | Grimsby Town | 11 December 1967 |
| 9 | Luton Town | 2–1 | Oxford City | 14 December 1967 |
| 10 | Swindon Town | 4–0 | Salisbury | 12 December 1967 |
| 11 | Shrewsbury Town | 3–0 | Darlington | 13 December 1967 |
| 12 | Tranmere Rovers | 5–1 | Rochdale | 9 December 1967 |
| 13 | Stockport County | 1–1 | Macclesfield Town | 9 December 1967 |
| Replay | Macclesfield Town | 4–1 | Stockport County | 13 December 1967 |
| 14 | Leytonstone | 0–1 | Walsall | 9 December 1967 |
| 15 | Brentford | 2–2 | Guildford City | 14 December 1967 |
| Replay | Guildford City | 2–1 | Brentford | 18 December 1967 |
| 16 | Lowestoft Town | 0–1 | Watford | 9 December 1967 |
| 17 | Brighton & Hove Albion | 1–0 | Southend United | 13 December 1967 |
| 18 | Bradford City | 7–1 | Wrexham | 9 December 1967 |
| 19 | Wimbledon | 3–0 | Romford | 9 December 1967 |
| 20 | Goole Town | 0–0 | Spennymoor United | 9 December 1967 |
| Replay | Spennymoor United | 3–1 | Goole Town | 13 December 1967 |
| 21 | Hartlepools United | 2–3 | Bury | 9 December 1967 |
| 22 | Scunthorpe United | 2–0 | Skelmersdale United | 9 December 1967 |
| 23 | Tow Law Town | 5–1 | Mansfield Town | 13 December 1967 |
| 24 | Port Vale | 1–2 | Chester | 9 December 1967 |
| 25 | Halifax Town | 3–2 | Crewe Alexandra | 13 December 1967 |
| 26 | Newport County | 3–0 | Gillingham | 18 December 1967 |
| 27 | Swansea Town | 2–0 | Enfield | 18 December 1967 |
| 28 | Southport | 3–1 | Lincoln City | 9 December 1967 |
| 29 | Runcorn | 1–0 | Notts County | 9 December 1967 |
| 30 | Torquay United | 1–1 | Colchester United | 12 December 1967 |
| Replay | Colchester United | 2–1 | Torquay United | 18 December 1967 |
| 31 | Walthamstow Avenue | 2–1 | Kidderminster Harriers | 9 December 1967 |
| 32 | York City | 0–1 | Doncaster Rovers | 9 December 1967 |
| 33 | Hereford United | 3–2 | Barnet | 13 December 1967 |
| 34 | Peterborough United | 5–2 | Falmouth Town | 11 December 1967 |
| 35 | Chelmsford City | 3–3 | Oxford United | 9 December 1967 |
| Replay | Oxford United | 3–3 | Chelmsford City | 13 December 1967 |
| 2nd replay | Chelmsford City | 1–0 | Oxford United | 18 December 1967 |
| 36 | Nuneaton Borough | 0–0 | Exeter City | 9 December 1967 |
| Replay | Exeter City | 0–0 | Nuneaton Borough | 13 December 1967 |
| 2nd replay | Nuneaton Borough | 0–1 | Exeter City | 18 December 1967 |
| 37 | Corby Town | 0–4 | Boston United | 9 December 1967 |
| 38 | Dagenham | 1–0 | Tonbridge | 9 December 1967 |
| 39 | Ryhope Colliery Welfare | 0–1 | Workington | 9 December 1967 |
| 40 | Arnold | 0–3 | Bristol Rovers | 9 December 1967 |
Question:
What was the tie no when Wrexham was the away team?
Answer:
18.0