Can someone help me writh this query "select x when mean y is greater than 10 unit during last 2 years and less than mean 10 during last 3 days

I am analysing Air pollution data and our aim is to identify individuals who seek health care during last 7 years at 150 PH clinics. i want to identify individual who visited first time during these 7 years and whether air pollution level at monitoring station close to them was greater then 10 unit during last 2 years and greater then or less then 10 units during last 3 days. or in other words

"select x when mean y is greater than 10 unit during last 2 years and less than mean 10 during last 3 days?