From https://en.wikipedia.org/wiki/Libor_scandal https://en.wikipedia.org/wiki/Libor_scandal , looks like it was pretty relevant from 2000 onwards at least. Th

From https://en.wikipedia.org/wiki/Libor_scandal https://en.wikipedia.org/wiki/Libor_scandal , looks like it was pretty relevant from 2000 onwards at least. The excerpt below seems to strongly indicate manipulation designed to improve banks profits over a long period of time "Statistical analysis indicated that the Libor rose consistently on the first day of each month between 2000 and 2009 on the day that most adjustable-rate mortgages had as a change date on which new repayment rates would "reset". An email referenced in the lawsuit from the Barclay's settlement, showed a trader asking for a higher Libor rate because "We're getting killed on our three-month resets." During the analysed period, the Libor rate rose on average more than two basis points above the average on the first day of the month, and between 2007 and 2009, the Libor rate rose on average more than seven and one-half basis points above the average on the first day of the month." Also from https://www.bloomberg.com/news/articles/2013-01-28/libor-lies-revealed-in-rigging-of-300-trillion-benchmark https://www.bloomberg.com/news/articles/2013-01-28/libor-lie... "At Barclays, derivatives traders made 257 requests for U.S.-dollar Libor, yen Libor and euro interbank offered rate, or Euribor, submissions from January 2005 to June 2009, " So whilst it may be true that it became more relevant after 2007, it seems be that there were some elements of this that were longer standing.