## Indicator list

Such as 450 120 553 994 334 844 675 496
(`120 334 450 496 553 675 844 994`)

### count

count of the items processed
The total number is 8 here.

### max/upper

The largest value

The maximum value, here is 994

### min/lower

The smallest value

Minimum value, here is 120

### sum

Total of items

The sum total, here is 4466

### mean

average of the items

The average value here is 558.25

### sum_90

The sum of values up to the 90th percentile

In ascending order of size, the sum of the first 90% data, here is 3472 (`4466-994`)

### upper_90

The upper value of the 90th percentile group

In ascending order of size, the largest number in the first 90% data, here is 844

### mean_90

The average of values up to the 90th percentile

In ascending order of size, the average value of the first 90% data, here is 496

### 90thPercentile

A group of n observation values are arranged according to the numerical value, and the value at the p% position is called the p hundredth digit. Percentile is usually expressed by the hundredth percentile, such as the fifth percentile, which means that the cumulative frequency of measured values is 5% in all measured data.

Percentile provides information about how each data item is distributed between the minimum and maximum values. For data without a large number of repetitions, the p percentile divides it into two parts. About p% of data items have values smaller than the p percentile; While about (100-p)% of the data items have values greater than the p percentile.
90% response time, which means, for example, 90% response time in an hour is 500ms, indicating that 90% of the response time for all requests for the page in this hour is less than or equal to 500 ms.

• Calculation method

Let a sequence be supplied with n numbers and require (k%) percent:
(1) sort from small to large, find (n-1)*k%, remember the integer part as I, decimal part as j (`Here 7*0.9=6.3, I is 6, and j is 0.3`)
(2) the result = (1-j)Number (i+1)+jNumber (i+2) (here 0.7844+0.3994=889)
Pay special attention to the following two most likely situations:
(1)j is 0, that is, (n-1)*k% is exactly an integer, then the result is exactly the (i+1) th number
(2) The (i+1) th number is equal to the (i+2) th number, which is known without calculation.