Unknown fields in output of vacuum explores

[moseleyi]

I was running vacuum on a specific explores and looked up the result of the API call and realised there's a lot of this:

 1, '51.68': 1, '207.227': 1, '74.71': 1, '165.43': 1, '84.227': 1, '99.92': 1, '88.105': 1, '60.133': 1, '2.43': 1, '198.14': 1, '141.48': 1, '25.71': 1, '5.90': 1, '128.221': 1, '80.194': 1, '86.114': 1, '89.242': 1, '119.165': 1, '46.25': 1, '217.205': 1, '249.90': 1, '31.159': 1, '210.104': 1, '95.169': 3, '226.109': 2, '220.168': 1, '86.0': 1, '230.210': 1, 'gmx.de': 15, 'immobilien.de': 7, 'live.de': 5, 'neel.popat1': 1, 'l.koglin': 1, 'g.stobbard': 1, 'bertram.clemens': 1, 'jonathan.victor744': 1, 'janhirte.com': 1, 'peter.schonauer': 2, 'gmx.net': 3, 'freenet.de': 3, 'marie.rossier': 1, 'design.de': 1, 'yahoo.de': 5, 'Uta.Rauch': 1, 'julianroy.com': 1, 'web.de': 7, 'vicky.bluemel': 1, 'wohnung.mail': 1, 'kimfleskes.de': 1, 'mate.de': 2, 'Wandrey.philomenis': 2, 'praxis.eu': 1, 'tim.schmelt': 1, 'ucm.es': 1, 's.tacke': 2, 'frankschwaiger.com': 1, 'ti.wo': 1, 'schempp.immobilien':

These are deifinitely not fields in my explore. The output comes from get_used_explore_fields