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:
| Vacuum range | Pressure in hPa (mbar) | Molecules / cm 3 | Molecules / m 3 | Mean free path |
| --- | --- | --- | --- | --- |
| Ambient pressure | 1013 | 2.7 × 10 19 | 2.7 × 10 25 | 68 nm |
| Low vacuum | 300 – 1 | 10 19 – 10 16 | 10 25 – 10 22 | 0.1 – 100 μm |
| Medium vacuum | 1 – 10 −3 | 10 16 – 10 13 | 10 22 – 10 19 | 0.1 – 100mm |
| High vacuum | 10 −3 – 10 −7 | 10 13 – 10 9 | 10 19 – 10 15 | 10cm – 1km |
| Ultra high vacuum | 10 −7 – 10 −12 | 10 9 – 10 4 | 10 15 – 10 10 | 1km – 10 5 km |
Question:
What is the pressure in ultra high vacuum?
Answer:
10 −7 – 10 −12