Extracting numbers from a series of text files

I have 12 files all with the same format:

Statistics Information

Line: 4
Fiducial range: 156 to 364

Number of items: 209
Number of dummies: 0
Minimum value: -0.08983668870989447
Maximum value: 0.059795797205623558
Mean value: -0.00884060126461031
Standard deviation: 0.03707261357656038
Arithmetic sum: -1.8476856643035546

Each file is for a manoeuvre in a specific direction, North (Pitch, roll, Yaw), South (Pitch, roll, Yaw), East (Pitch, roll, Yaw) and West (Pitch, roll, Yaw).

I want to cycle through each of these text files and store the number for each minimum, maximum and mean value for each file. Then export them in a table:

et cetera

So far I have managed to list the different files and then extract the first line:

import glob

txt_files = glob.glob("*.txt")

def read_first_line(txt_files):
     with open(txt_files, 'rt') as fd:
         first_line = fd.readline()
     return first_line
output_strings = map(read_first_line, txt_files)  # apply read first line function all text files
print(txt_files)
output_content = "".join(sorted(output_strings))
output_content  # as a string
print(output_content)  # print as formatted
with open('outfile.txt', 'wt') as fd:
    fd.write(output_content)