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:
| Standard | Date | CO (g/kWh) | NO x (g/kWh) | HC (g/kWh) | PM (g/kWh) |
| --- | --- | --- | --- | --- | --- |
| Euro 0 | 1988–1992 | 12.3 | 15.8 | 2.6 | none |
| Euro I | 1992–1995 | 4.9 | 9.0 | 1.23 | 0.40 |
| Euro II | 1995–1999 | 4.0 | 7.0 | 1.1 | 0.15 |
| Euro III | 1999–2005 | 2.1 | 5.0 | 0.66 | 0.1 |
| Euro IV | 2005–2008 | 1.5 | 3.5 | 0.46 | 0.02 |
Question:
What's the NO of the standard with HC of 1.23 g/kWh?
Answer:
9.0