COUNTIFS counts the number of occurrences that meet one or more conditions. All conditions must be be for the occurrence to be counted. The conditions in this case are:

A2:A16,">="&0.15

The value is greater than or equal to 0.15

A1:A15,"<"&0.15

The preceding value is less than 0.15



The ranges in a COUNTIFS formula must all be the same shape. In the first condition, it is all values starting with the second value. This is where we look to see if a value reached 0.15. In the second condition, we start with the first value, and go to the next-to-last value. This is where we look to see if a value is less than 0.15. Because both conditions must be true, the occurrence that will be counted if a number is >= 0.15 and the previous number is < 0.15.