Number of Hours to Achieve level.  Note finishing 20, 30, and 35.  A Total of 22% of total play time was spent on these three levels.

Number of Hours to achieve level, line view.

Total number of hours played, by level.

Each total played from  the chart of numbers from the previous page are the TOTAL time to achieve that level.  So, for example, 31st level took 83 hours to achieve.   Or, in other words, it took 83 hours to get through level 30.

The numbers are calculated by:

1.  Each Level is translated into a number of total minutes played since starting EQ.  The formula is: 
Mp = (D * 24 * 60) + (H * 60) + M

2.  The total minutes played for each level is then subtracted from the next levels, getting the total minutes between levels.

3.  This is then calculated to the number of hours (Hl = Mp / 60).   The Hours Played for a Level is rounded to tens.

I have only been tracking this info from level 13.  There are two things of note.

1.  Hell levels do seem to exist.  20, 30, and 35 took almost double the amount of time of the other levels.  The oddity here is 25 did not take as long.   I'm not sure what's up with this.

2.  The slope(1.017)  is rather scary... For example, it looks like the play time for 46rd level will be something like 59 days, and 50th level will take 62 days.