Odd distribution in Net Promoter Score data



I've got 6 years of NPS data from quarterly surveys using the common 1-10 scale. The distribution of the quarterly raw scores consistently resembles the left half of a normal distribution so the raw scores are certainly not normally distributed and look more like a heavily negative skewed distribution or maybe a beta distribution. Either way, I have no idea how to interpret this. Thoughts and suggestions are appreciated.

The data for a typical histogram chart looks like this:
Bin Frequency
1 1
2 0
3 2
4 1
5 2
6 5
7 8
8 9
9 15
10 24

I'm aware of the limitations of using the NPS measure.