Table 9: Number of metrics per study.

N of metrics	N of papers	Papers
1	5	[23, 27, 29, 31, 40]
2	4	[16, 17, 20, 35]
3	5	[25, 26, 32, 41, 42]
4	2	[19, 43]
5	6	[21, 30, 34, 36, 37, 39]
6	2	[24, 33]
7	2	[28, 38]
8	1	[18]