[Aetae]

Судя по докам делать надо так:

var data = [
                        {
                            "category": "Первое значение",
                            "column-1": "78787878",
                            "color": "#DCD36A"
                        },
                        {
                            "category": "Второе значение",
                            "column-1": "78787878",
                            "color": "#EE204D"
                        },
                        {
                            "category": "Третье значение",
                            "color": "#77DD77",
                            "column-1": "78787878"
                        }
                    ];

var chart =  AmCharts.makeChart("chartdiv",
                {
                    "type": "serial",
                    "path": "http://www.amcharts.com/lib/3/",
                    "categoryField": "category",
                    "maxSelectedTime": -2,
                    "startDuration": 1,
                    "decimalSeparator": ",",
                    "categoryAxis": {
                        "gridPosition": "start",
                        "position": "top",
                        "title": "Аналитический отчет",
                        "titleColor": "#000000",
                        "titleFontSize": 15
                    },
                    "trendLines": [],
                    "graphs": [
                        {
                            "colorField": "color",
                            "fillAlphas": 1,
                            "id": "AmGraph-1",
                            "lineColorField": "color",
                            "title": "graph 1",
                            "type": "column",
                            "valueField": "column-1"
                        }
                    ],
                    "guides": [],
                    "valueAxes": [
                        {
                            "id": "ValueAxis-1",
                            "maximum": 30000000,
                            "minimum": 1,
                            "axisThickness": 0,
                            "color": "#4B0082",
                            "fontSize": 13,
                            "gridThickness": 0,
                            "labelRotation": -3.6,
                            "minHorizontalGap": 73,
                            "showFirstLabel": false,
                            "showLastLabel": false,
                            "tickLength": 3,
                            "title": "Руб. ",
                            "titleBold": false,
                            "titleFontSize": 1
                        }
                    ],
                    "allLabels": [],
                    "balloon": {},
                    "titles": [],
                    "dataProvider": data
                }
            );


//после получения новых жанных из php делать следующее:
data[0]['column-1'] = новые_цифры;
chart.validateData();