Table 4. Amino Acid substitutions of the Seven Regions of HN Gene (calculated using all available sequences from GenBank).

Region Name	Location of region	Length of the region (Residues)	No. of Substitutions in each region	Ratio of substitution/residue
Cytoplasmic tail	1–35	35	4	0.114
Transmembrane region	36–60	25	4	0.160
Stalk region	61–191	131	9	0.069
High structural homology region I	192–341	150	5	0.033
Non-structural assignment region	342–457	116	12	0.103
High structural homology region II	458–504	47	3	0.064
Carboxyl terminal	505–575	71	11	0.155