Table 1.

Lists of most frequent, most harmful variations (gray columns, with degree of harmfulness > 50% and frequency > 0.5%) and most frequent, least harmful variations (with degree of harmfulness less than 20% and frequency > 0.5%)

Variation	Frequency (%)	Degree of Harmfulness	Variation	Frequency (%)	Degree of Harmfulness
RC	2.52	0.52	VI	1.82	0.10
GR	2.39	0.59	IV	1.47	0.08
RW	2.18	0.53	TA	1.33	0.13
LP	2.06	0.63	VA	1.07	0.17
GD	1.27	0.57	LV	0.93	0.19
YC	1.13	0.59	SN	0.90	0.19
GE	1.04	0.53	KR	0.82	0.16
CY	0.96	0.67	ED	0.81	0.16
GV	0.95	0.61	DE	0.69	0.19
CR	0.93	0.63	SG	0.64	0.15
RP	0.74	0.63	AS	0.62	0.16
LR	0.65	0.60	RK	0.58	0.12
WR	0.56	0.56	EQ	0.58	0.18
FS	0.54	0.52	TS	0.55	0.10