pre_text: 22. Cash and cash equivalents Cash at bank earns interest at floating interest rates. Of the total cash and cash equivalents balance, $79.3 million (2018 $63.9 million) is callable at notice of three months or less at the date of investment. Short-term bank deposits are made for varying periods of between one day and three months depending on the cash requirements of the Group and earn interest at the short-term deposit rates appropriate for the term of the deposit and currency. At the end of 2019, the currency split of cash and cash equivalents was US Dollar 78 per cent (2018 83 per cent), Sterling 11 per cent (2018 8 per cent) and other currencies 11 per cent (2018 9 per cent). For the purposes of the cash flow statement, cash and cash equivalents comprise the above amounts.
table: 2019 2018
table: $ million $ million
table: Cash at bank 103.9 57.7
table: Short-term bank deposits 79.3 63.9
table: 183.2 121.6
question: Analyse this data from a financial earnings document. What was the change in the cash at bank?