Interpretation of this Part
10. In this Part and in Schedule 1—
“the baseline period” has the meaning given in regulation 7;
“population exposure” means population exposure to PM2.5;
“the Population Exposure Indicator”—
for the baseline period is a measure of average population exposure in that period;
for a year from 2019 onwards is a measure of average population exposure in the three-year period ending on 31st December in that year,
calculated in accordance with Schedule 1;
“the Reference Indicator” for a year is a measure of average population exposure in the three-year period ending on 31st December in the preceding year, calculated in accordance with Schedule 1 and to be used only for the purposes of making the determination required by regulation 8(1)(a) and the calculations required by paragraphs 1(d) and 2(c) of Schedule 1.