If you had the ability to add a column like “number of players missing per match”, and then the average for that month, you could somewhat adjust for that.
For instance, I’d be willing to bet that the bad November and December points percentages aligned with long injury lists on average. Where as the bad points percentages in March and April didn’t, as JHT’s performance teetered.
Interestingly, if you take JHT’s points haul up to February and average the percentage (46%) and assume he didn’t have the bad run, then points haul for the season would have been 64 - so still not enough for playoffs