a significant trendp-value = 0.005
There was also a significant trend in the proportion of types 16 and 18 with calendar time, with a higher proportion in the more recent years (p-value = 0.005) (Table 4 ), with no heterogeneity among centres.
There was also a significant trend in the proportion of types 16 and 18 with calendar time, with a higher proportion in the more recent years (p-value = 0.005) (Table 4 ), with no heterogeneity among centres.