Tumour growth data (tumour spheroids)

data=
{{4.56,       1.6308  },
{5.66,           3.2148  },  
{6.68,           5.614  }, 
{7.89,         11.8598  },
{8.81,         20.15  },
{9.79,         27.538  },
{10.99,       34.546  },
{11.99,       66.08  },
{12.86,       78.932  },
{15.17,     155.  },
{16.17,     231.44  },
{17.41,     334.38  },
{18.33,     565.14  },
{19.37,     721.28  },
{20.40,     789.46  },
{22.15,   1085.36  },
{23.16,   2129.6  },
{24.01,   2030.4  },
{25.22,   2447.8  },
{27.52,   2756.4  },
{28.27,   2714.  },
{29.26,   2905.6  },
{30.31,   3405.4  },
{31.41,   3900.4  },
{32.36,   4914.  },
{33.36,   5669.2  },
{34.29,   5826.6  },
{36.18,   6149.4  },
{38.19,   7119.4  },
{39.98,   9024.6  },
{42.08, 10854.2  },
{44.39, 12050.  },
{45.44, 10749.2  },
{46.33, 13342.  },
{47.38, 15646.  },
{48.73, 17126.  },
{51.08, 13246.6  },
{52.15, 14938.  },
{53.09, 17660.  },
{55.10, 19030.  },
{56.44, 20272.  },
{57.45, 17346.  },
{59.58, 17510.  },
{61.79, 18790.  },
{63.82, 18518.  },
{67.01, 19186.  },
{67.98, 21640.  },
{70.17, 18446. }};