It means a total of 134 finds have been reported in Nottinghamshire since records began in 2012.
The British Museum said restrictions on people’s exercise during coronavirus lockdowns contributed to a boost in unexpected garden discoveries last year.
More than 6,000 finds – which could include a single object or a hoard of coins – were recorded with the museum's Portable Antiquities Scheme during the first lockdown, when hunting with a metal detector outside the home was banned.
Former culture minister Caroline Dinenage said it was ‘brilliant’ to see the scheme grow during lockdown, thanks to garden finds and digital reporting.
Anyone who thinks they have struck a hidden hoard has to tell the coroner within two weeks, so they can hold an inquest to decide whether it constitutes treasure and who will receive the items.
If they do not, they face an unlimited fine, or up to three months’ jail.
Museums are given the chance to purchase any pieces a coroner rules as treasure, but the finder does not leave empty-handed – they will be paid a sum depending on the haul’s value.
In 2020, 115 finds were reported across the East Midlands.
The Treasure Act currently defines treasure as finds older than 300 years and made of gold or silver, or artefacts made of precious metals.
However, the Government announced last December a new definition would be introduced to protect treasure from being lost to the public. It would see artefacts also defined as treasure if they are ‘of historical or cultural significance’.
Metal detecting is the best way to unearth lost treasure, according to the figures.
The devices tracked down 96 per cent of finds in 2019.
A further 3 per cent – 36 cases – were archaeological finds and 10 from field walking or scouring streams and shores. Police recovered one treasure trove from a ‘nighthawker’, an illegal treasure hunter.