Description of elements in the header
y_rs	yearly precipitation amount
y_rsh	yearly precipitation amount from snow
y_rx	daily maximum precipitation amount in the year
y_rxd	the day with the daily maximum precipitation amount
y_dr01	number of days with precipitation amount ≥ 0.1 mm
y_dr1	number of days with precipitation amount ≥ 1 mm
y_dr5	number of days with precipitation amount ≥ 5 mm
y_dr10	number of days with precipitation amount ≥ 10 mm
y_dr20	number of days with precipitation amount ≥ 20 mm
y_dr30	number of days with precipitation amount ≥ 30 mm
y_dr50	number of days with precipitation amount ≥ 50 mm
y_drho	number of snowy days when the code of precipitation type is 4 or 5 or 8
y_drjeg	number of icy days when the code of precipitation type is 6 or 9
y_drziv	number of thundery days when the code of precipitation type is 7 or 9
y_dron	number of days with freezing days when the code of precipitation type is 2