data = [
{ year: 2000, weight: 3, number: 3 },
{ year: 2000, weight: 7, number: 7 },
{ year: 2000, weight: 7, number: 4.3 },
{ year: 2000, weight: 8, number: 9 },
{ year: 2000, weight: 8, number: 9.1 },
{ year: 2000, weight: 9, number: 6 },
{ year: 2000, weight: 9, number: 6 },
{ year: 2000, weight: 10, number: 5.1 },
{ year: 2000, weight: 10, number: 8.24 },
{ year: 2000, weight: 11, number: 2 },
{ year: 2000, weight: 11, number: 1 },
{ year: 2001, weight: 3, number: 5 },
{ year: 2001, weight: 7, number: 7 },
{ year: 2001, weight: 7, number: 7 },
{ year: 2001, weight: 8, number: 7 },
{ year: 2001, weight: 8, number: 4 },
{ year: 2001, weight: 9, number: 2 },
{ year: 2001, weight: 9, number: 4 },
{ year: 2001, weight: 10, number: 3 },
{ year: 2001, weight: 10, number: 8 },
{ year: 2001, weight: 11, number: 9 },
{ year: 2001, weight: 11, number: 4 },
{ year: 2001, weight: 16, number: 7.5 }
]