A visual guide to the different Score Methods
Sum
Sum will sum all scores during the scoring period (Default)
Sum - ignore period
Sum - ignore period - will sum all data entries ever stored

Sum - difference
Sum - Difference - will return the difference between the sum of data entries for this period with the sum of data entries for the previous period

Latest
Latest will use the most recent score entry in the current period

Latest - ignore period
Latest - ignore period will use the most recent score entry no matter when it was scored

Latest - difference
Latest - Difference will take the difference between the last score entry of the previous period and the most recent score entry for the current period.
Highest Score in Period
Highest Score in Period will take only the highest score as the entry for the period.

Lowest Score in Period
Lowest Score in Period will take only the lowest score as the entry for the period.

Average Score in Period
Average Score in Period will take the mean of all data entries for the period
Note that the "ignore period" score methods also affects the 92 day data entry deletion rule and will mean that data entries are not deleted after the 92 day data storage period expires.