Rough estimate from average emission factors per transport mode — see
js/carbon.js. A leg with no recorded mode is left out of its
year's total rather than guessed at; a year missing legs is marked
≥ and named in its tooltip.
Distance travelled per year
Year
Legs
Distance
Trips per year
Year
Trips
Legs
Distance
A trip is counted under the year it started — legs and
kilometres above are counted by the year they actually happened in, so a
trip crossing New Year contributes to two years there but one here.