Table 1. Highest posterior density (HPD) width in years of the node leading to the re-emergent H1N1 lineage before and after a 27-year shift in sampling dates.
| Segment | HPD width (reported sampling years) | HPD width (27-year shift for re-emergent lineage) | Ratio of HPDs (reported:shift) |
| HA | 4.48 | 2.55 | 0.57 |
| M | 5.96 | 6.41 | 1.07 |
| NAa | 27.31 | 2.26 | 0.08 |
| NA-mode 1 | 3.17 | – | 0.71 |
| NA-mode 2 | 4.48 | – | 0.49 |
| NP | 6.42 | 4.17 | 0.65 |
| NS | 5.18 | 3.54 | 0.68 |
| PA | 4.65 | 2.95 | 0.64 |
| PB2 | 5.20 | 3.09 | 0.59 |
a
NA had a bimodal distribution for the age of the node leading to re-emergent H1N1 lineage. Mode 1 was 1973–1977 and mode 2 was 1949–1953. Inclusion of either mode does not alter the pattern of significantly decreased variance following the 27-year shift.