get line count of yml list

[GewoonQuint]

So I'm trying to loop a yml list to get the highest rated player, making a leaderboard.
I use a yml list to store the elo points

elo:
  BuildUHC:
    8580db88-d6c3-42a6-81af-0ec6f055ecc8: 979.0
    ff576433-4e28-4e3d-954e-04d967766744: 1021.0

        set {_count} to yml value "elo.BuildUHC" of file "plugins/x/playerdata.yml"'s line count
        set {_c} to {_count}
        loop {_count} times:
            set {_current} to file "plugins/xydar/playerdata.yml"'s line {_c}
            remove 1 from {_c}
            set {_value} to subtext of {_current} from 1 to 36
            add {_value} to {_values::*}
        loop {_values::*}:
            set {_arg} to loop-value
            set {_trimmed} to "%(subtext of {_arg} from characters 0 to 8)%%(subtext of {_arg} from characters 10 to 13)%%(subtext of {_arg} from characters 15 to 18)%%(subtext of {_arg} from characters 20 to 23)%%(subtext of {_arg} from characters 25 to 36)%"
            set {_u} to text from "https://api.mojang.com/user/profiles/%{_trimmed}%/names"
            set {_a::*} to {_u} split at """"
            loop {_a::*}:
                loop-value-2 isn't "[{"
                loop-value-2 isn't "name"
                loop-value-2 isn't ":"
                loop-value-2 isn't "}]"
                set {_p} to loop-value-2 parsed as offline player
                message "%{_p}%" #

so how do you get the line count of a yml list?