year	group	freq
2015	HB	35
2015	LB	61
2015	SB	4
2016	HB	36
2016	LB	14
2016	SB	51
2017	HB	9
2017	LB	87
2017	SB	4
2018	HB	65
2018	LB	5
2018	SB	29