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| 1995 | 2000 | 2005 | 2010 | 2015 | 2020 | |
|---|---|---|---|---|---|---|
| Trial outcome reports | 17 | 28 | 122 | 425 | 716 | 718 |
| Secondary/follow-up | 0 | 3 | 4 | 10 | 112 | 177 |
| Study protocols | 0 | 0 | 2 | 25 | 122 | 233 |
| Methodology | 4 | 12 | 44 | 57 | 79 | 99 |
| Trial logistics | 0 | 0 | 4 | 6 | 8 | 6 |
| Other relevant | 0 | 4 | 4 | 0 | 8 | 7 |
