Study the table below, which shows the change in employment structure for a rapidly transitioning economy between 1980 and 2020.
| Year | Primary industry (%) | Secondary industry (%) | Service industry (%) |
|---|---|---|---|
| 1980 | 56 | 15 | 29 |
| 1990 | 44 | 18 | 38 |
| 2000 | 32 | 22 | 46 |
| 2010 | 22 | 25 | 53 |
| 2020 | 13 | 24 | 63 |
Which one of the following describes the change in employment in primary industry from 1980 to 2020?
It decreases to less than a quarter of its 1980 value
It halves
It decreases to less than a tenth of its 1980 value
It decreases to exactly a third of its 1980 value
