import re
pattern = r"\b(?:lower|upper) quartile \d+(?:,\d+)?\b"
s = "(....) partijen waarvan de lower quartile 0,68% bedraagt en de upper quartile 2,06%."
print(re.findall(pattern, s))
aW1wb3J0IHJlCgpwYXR0ZXJuID0gciJcYig/Omxvd2VyfHVwcGVyKSBxdWFydGlsZSBcZCsoPzosXGQrKT9cYiIKcyA9ICIoLi4uLikgcGFydGlqZW4gd2FhcnZhbiBkZSBsb3dlciBxdWFydGlsZSAwLDY4JSBiZWRyYWFndCBlbiBkZSB1cHBlciBxdWFydGlsZSAyLDA2JS4iCgpwcmludChyZS5maW5kYWxsKHBhdHRlcm4sIHMpKQ==