_id	Year	Obs	Survey	Adults	Cygnets
1	2017	Mark	1	5167	2939
2	2017	Mark	2	4779	3251
3	2017	Sophie	1	4850	2891
4	2017	Sophie	2	5110	3059
5	2018	Mark	1	5756	1451
6	2018	Mark	2	5538	1586
7	2018	Oscar	1	5395	1495
8	2018	Oscar	2	5983	1660
9	2019	Mark	1	6845	2159
10	2019	Mark	2	6426	2143
11	2019	Laura	1	5674	2062
12	2019	Laura	2	5776	2047