A fluorine disposal plant was constructed to carryout the reactions :
`F_(2)+2NaOH rarr 1/2 O_(2)+2NaF+H_(2)O`
`2NaF+CaO+H_(2)O rarr CaF_(2)+2NaOH`
As the plant operated, excess lime was added to bring about complete precipitation of the fluoride as `CaF_(2)`. Over a period of operation, 1900 kg of fluorine was fed into a plant and 10,000 kg of lime was required. What was the percentage utilisation of lime ? [ At mass F = 19 ], [Lime : CaO]