From outside the United Kingdom and the United States, the Canadian trio Rush released three distinctively hard rock albums in 1974–75 (Rush, Fly by Night and Caress of Steel) before moving toward a more progressive sound with the 1976 album 2112. The Irish band Thin Lizzy, which had formed in the late 1960s, made their most substantial commercial breakthrough in 1976 with the hard rock album Jailbreak and their worldwide hit "The Boys Are Back in Town", which reached number 8 in the UK and number 12 in the US. Their style, consisting of two duelling guitarists often playing leads in harmony, proved itself to be a large influence on later bands. They reached their commercial, and arguably their artistic peak with Black Rose: A Rock Legend (1979). The arrival of Scorpions from Germany marked the geographical expansion of the subgenre. Australian-formed AC/DC, with a stripped back, riff heavy and abrasive style that also appealed to the punk generation, began to gain international attention from 1976, culminating in the release of their multi-platinum albums Let There Be Rock (1977) and Highway to Hell (1979). Also influenced by a punk ethos were heavy metal bands like Motörhead, while Judas Priest abandoned the remaining elements of the blues in their music, further differentiating the hard rock and heavy metal styles and helping to create the New Wave of British Heavy Metal which was pursued by bands like Iron Maiden, Saxon and Venom.

Answer this question, if possible (if impossible, reply "unanswerable"): When did the American band Lizzy moved to Ireland?
unanswerable