There is a call center which records the number of complaints against a service on daily basis.
For example, the values below show the number of complaints in a month
I am not trying to estimate anything here. By looking at the graph i can see that the overall values are increasing from right to left. I don't know much statistics other than mean, median, mode so i phrased it as "increasing nature". I want a single numeric value (e.g. standard deviation) which would let me know if it is a straight horizontal line or going downwards or going upwards from left to right.
For example, suppose there is a function XYZ (which i am looking for) which receives this dataset and returns a numeric value from 0 to 100. 0 means the highly decreasing nature, 50 means straight line and 100 means highly increasing nature. If the graph is increasing and decreasing symmetrically across a horizontal line then the result would be 50 (as an average of increasing and decreasing natures). If the graph has more increasing nature then decreasing then the result would be > 50 and vice versa. Following are some sample graphs
Question: How can I quantify increasing nature of this given data?