Graph
| Year | Totals | Observation hours |
|---|---|---|
| 1997 | 1 | 39:30 |
| 1999 | 0 | 19:00 |
| 2001 | 127 | 594:30 |
| 2002 | 0 | 0:00 |
| 2005 | 1 | 77:15 |
| 2006 | 0 | 32:05 |
| 2007 | 0 | 88:45 |
| 2008 | 5 | 100:00 |
| 2009 | 0 | 52:20 |
| 2010 | 3 | 48:05 |
| 2011 | 0 | 88:24 |
| 2012 | 3 | 36:20 |
| 2013 | 1 | 37:30 |
| 2014 | 1 | 30:40 |
| 2015 | 0 | 44:40 |
| 2016 | 24 | 163:00 |
| 2017 | 11 | 179:29 |
| 2018 | 9 | 380:50 |
| 2019 | 6 | 344:15 |
| 2020 | 9 | 447:51 |
| 2021 | 9 | 462:39 |
| 2022 | 9 | 482:00 |
