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:
| Team | Played | Draw | Lost | Goals For | Goals Against | Goal Difference | Points |
| --- | --- | --- | --- | --- | --- | --- | --- |
| FH | 18.0 | 7.0 | 1.0 | 33.0 | 16.0 | 17.0 | 37.0 |
| ÍBV | 18.0 | 4.0 | 5.0 | 35.0 | 20.0 | 15.0 | 31.0 |
| ÍA | 18.0 | 7.0 | 3.0 | 28.0 | 19.0 | 9.0 | 31.0 |
| Fylkir | 18.0 | 5.0 | 5.0 | 26.0 | 20.0 | 6.0 | 29.0 |
| Keflavík | 18.0 | 3.0 | 8.0 | 31.0 | 33.0 | -2.0 | 24.0 |
| KR | 18.0 | 7.0 | 6.0 | 21.0 | 22.0 | -1.0 | 22.0 |
| Grindavík | 18.0 | 7.0 | 6.0 | 24.0 | 31.0 | -7.0 | 22.0 |
| Fram | 18.0 | 5.0 | 9.0 | 19.0 | 28.0 | -9.0 | 17.0 |
| Víkingur | 18.0 | 4.0 | 10.0 | 19.0 | 30.0 | -11.0 | 16.0 |
| KA | 18.0 | 3.0 | 11.0 | 13.0 | 30.0 | -17.0 | 15.0 |
Question:
Tell me the totla number of goal difference for goals against of 30 and played less than 18
Answer:
0.0