Formula
From Fallen London Wiki
I got 29610 Service from 2461 Surveys and 4 Sightings, so the formula is most likely 10 * Surveys + 1250 * Sightings.
(The only other positive integer solutions to 2461x + 4y = 29610 are (x, y) = (2, 6172) and (x, y) = (6, 3711), which seem ... unlikely.)
