Counting the number of symbols in the lyr

Counting the number of symbols in the lyr displays 0 count while it counts them in the total count. I have 253 unique values in my F.C and I have created a symbology layer for them and imported it, when I hit count to find the values that didn’t take symbol 2 values was missing and this is ok for me, but when I have a look at the count values I found that some values takes the value 0 not 1, and when I try to add values nothing displayed “except the 2 missing ones before”, noticing that the total count is 251, so I am now confused with this behavior why the ArcMAP displays 0 count while it counts them in the total count also it give them the symbol of my map, FYI the values which there count is 0 are included in the attribute table of my F.C