Why does this function print empty list?

[hhydration]

def kasinski(text):
    trigraphs=[]
    distances=[]
    for trigraph in range (len(text)-2):
        newtrigraph= text[trigraph:trigraph+3]
    if newtrigraph in trigraphs:
        distances.append(trigraph-(text.index(newtrigraph)))
    else:
        trigraphs.append(newtrigraph)
        trigraphs.append(trigraph)
        return distances

Can anyone identify why this function is returning "[]"? I am printing with the string "UZRZEGNJENVLISEXRHLYPYEGTESBJHJCSBPTGDYFXXBHEEIFTCCHVRKPNHWXPCTUQTGDJHTBIPRFEMJCNHVTCFSAIIJENREGSALHXHWZWRZXGTTVWGDHTEYXISAGQTCJPRSIAPTUMGZALHXHHSOHPWCZLBRZTCBRGHCDIQIKTOAAEFTOPYEGTENRAIALNRXLPCEPYKGPNGPRQPIAKWXDCBZXGPDNRWXEIFZXGJLVOXAJTUEMBLNLQHGPWVPEQPIAXATYENVYJEUEI"(this string does contain repeated trigraphs)