Table 3.

Nucleotide mutation rates of the seven nsp14 variants for each cluster in which the maximum number was observed

Ranking of nsp14	Substitution in nsp14	Lineage (PANGO ID)	Number of sequences containing the nsp14 substitution	Substitution rate per year in the whole genome
5	L177F	B.1.1.25	54	7.8
7	F377L	B	50	8.5
11	S369F	B.1.1	17	13.4
13	M501I	B.1	11	4.4
16	P203L	B.1.1.33	6	58.8
		B.1	6	28.0
17	L177F/T372I	B.1.113	20	50.1
18	P297S	B.4	11	16.1

The number of mismatched nucleotides in the alignment of the reference sequence with the comparison sequence of each group was counted, and the average value was calculated. hCoV-19/Wuhan/Hu-1/2019 was selected as the reference sequence. A scatterplot of these nsp14 is shown in Figures 2B and S5.