highly significantP < 0.001
Statistical analysis showed a highly significant difference ( P < 0.001) in the measured MIRs in Lower Saxony, and individual comparison of the MIRs from 2019 with the MIRs from 2020, 2021 and 2022 resulted in P -values of P = 0.00238 for 2019 versus 2020, P = 0.00033 for 2019 versus 2021 and P = 0.00329 for 2019 versus 2022.