Length[sf]

Take[sf,{1,20}]

tsf=Sort[Tally[sf]]

Show[Plot[ftest2[x],{x,-3.2,3.2},PlotStyle->Green],Plot[ftest[x],{x,-3.2,3.2},PlotStyle->Red],ListPlot[Sort[Tally[sf]]]]

nd[x_]:=PDF[NormalDistribution[a,b],x]

nd[0]

Fit[tsf,{1,x,x^2},x]

FindFit[tsf,A*1/(σ*Sqrt[2 π]) Exp[-(1/2) ((x-μ)/σ)^2],{σ,μ,A},x]

ftest[x_]:=752.7735711204767`/(1.2247300284408893`*Sqrt[2Pi])*Exp[-0.5*((x-0.06441366066806782`)/1.2247300284408893`)^2];

FindFit[tsf,A*1/(σ*Sqrt[2 π]) Exp[-(1/2) ((x)/σ)^2],{σ,A},x]

ftest2[x_]:=753.1178131082216`/(1.2275426309712474`*Sqrt[2Pi])*Exp[-0.5*((x)/1.2275426309712474`)^2];