import numpy as np
import matplotlib.pyplot as plt

fname = 'satcat_download.txt'

with open(fname, 'r') as infile:
    lines = infile.readlines()

dic = dict()

for line in lines:
    year, num = int(line[0:4]), int(line[5:8])
    try:
        dic[year].append(num)
    except:
        dic[year] = [num]

data = [(a, sorted(set(b))) for a, b in sorted(dic.items())]

if True:
    for a, b in data:
        print(a, len(b), b[-1], len(b) == b[-1])

years = np.array([x[0] for x in data])
number = np.array([len(x[1]) for x in data])
highest = np.array([x[1][-1] for x in data])

disagree = highest != number
yeardots = years[disagree]
numberdots = number[disagree]

plt.figure()
plt.plot(years, number)
plt.plot(years, highest)
plt.plot(yeardots, numberdots, 'ok', mfc='none', ms=20)
plt.show()