Price extension price unit.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v25/enums/price_extension_price_unit.proto)

| Enums ||
|---|---|
| ## `PER_DAY` | Per day. |
| ## `PER_HOUR` | Per hour. |
| ## `PER_MONTH` | Per month. |
| ## `PER_NIGHT` | Per night. |
| ## `PER_WEEK` | Per week. |
| ## `PER_YEAR` | Per year. |
| ## `UNKNOWN` | Used for return value only. Represents value unknown in this version. |
| ## `UNSPECIFIED` | Not specified. |