PBV and PTBV by quintiles

Using Sharelock Holmes, I decided to calculate the PBV (Price to Book Value) and PTBV (Price to Tangible Book Value) for stocks listed on the LSE having a market cap of over £100M. Here are the results in quintiles:

     PBV   PTBV
P20  1.13  1.64
P40  1.80  3.89
P60  2.76  8.81
P80  4.93  NEG

SH (Sharelock Holmes) returned 589 results. Negative values were given a value of 10000. There was only one null/blank in the stats - it's incosequential for me to determine its proper treatment. The resulting scores were ranked numerically, and the quintiles stated using the normal nomenclature (e.g. P20 stands for the 20th percentile).

In the sample, 3% of the companies had negative PBV, and fully 25% of the companies had negative PTBV (hence P80 shown as "NEG").