Table 1.

Failure categories for each year between 2013 and 2016

Failure category	Failure frequency for all machines at each year of the study period				Total	Average per year
	2013	2014	2015	2016
Software	9	14	7	3	33	8.25
Hardware
Input	6	4	2	2	14	3.5
Core	2	2	1	1	6	1.5
Output	7	9	5	3	24	6
US probe	8	13	6	4	31	7.75
Total	32	42	21	13	108	27

US: Ultrasound