Table 2a shows a manufacturer's monthly output and average costs in 2021 and 2022, in Canadian Dollars (CAD).
| 2021 | 2022 | |
|---|---|---|
| Monthly output (units) | 15 000 | 25 000 |
| Average cost per unit (CAD) | 6.00 | 4.50 |
What has happened to total monthly costs from 2021 to 2022? Show your workings.
