| Year | Companies |
|---|---|
| 1978 | 615 |
| 1982 | 538 |
| 1987 | 434 |
| 1992 | 351 |
| 1997 | 277 |
| 2002 | 175 |
| 2007 | 128 |
| 2012 | 92 |
| 2017 | 74 |
| 2019 | 70 |
| 2021 | 70 |
| 2022 | 70 |
| 2023 | 70 |
| 2024 | 69 |
| 2025 | 68 |
| Year | Companies |
|---|---|
| 1978 | 615 |
| 1982 | 538 |
| 1987 | 434 |
| 1992 | 351 |
| 1997 | 277 |
| 2002 | 175 |
| 2007 | 128 |
| 2012 | 92 |
| 2017 | 74 |
| 2019 | 70 |
| 2021 | 70 |
| 2022 | 70 |
| 2023 | 70 |
| 2024 | 69 |
| 2025 | 68 |