Graph 如何在tikz图片的圆圈上方绘制数字？

我正在使用tikz软件包绘制一个图形，我需要知道如何在圆上方插入一个数字，以指示每个数字在图形上的顺序。 以下是我目前得到的信息：

(1, 4) node[circle, black, draw](a){A}
(2.5, 4) node[circle, black, draw](b){B}
(4, 4) node[circle, black, draw](c){C}
(1, 2.5) node[circle, black, draw](d){D}
(2.5, 2.5) node[circle, black, draw](e){E}
(4, 2.5) node[circle, black, draw](f){F}
(1, 1) node[circle, black, draw](g){G}
(2.5, 1) node[circle, black, draw](h){H}
(4, 1) node[circle, black, draw](i){I};

---

我想确定的是节点A是第一个，B是第二个，C是第三个。。。直到最后一个，在其圆圈上方添加一个数字。

标签的语法是

label=[position]：[label\u text]

：

node[circle, black, draw, label=left:1](a){A}
(2.5, 4) node[circle, black, draw, label=above:2](b){B}
(4, 4) node[circle, black, draw, label=right:3](c){C}
(1, 2.5) node[circle, black, draw, label=below:4](d){D}
(2.5, 2.5) node[circle, black, draw, label=5](e){E}
(4, 2.5) node[circle, black, draw, label=6](f){F}
(1, 1) node[circle, black, draw, label=7](g){G}
(2.5, 1) node[circle, black, draw, label=8](h){H}
(4, 1) node[circle, black, draw, label=9](i){I};

---

标签的语法是

label=[position]：[label\u text]

：

node[circle, black, draw, label=left:1](a){A}
(2.5, 4) node[circle, black, draw, label=above:2](b){B}
(4, 4) node[circle, black, draw, label=right:3](c){C}
(1, 2.5) node[circle, black, draw, label=below:4](d){D}
(2.5, 2.5) node[circle, black, draw, label=5](e){E}
(4, 2.5) node[circle, black, draw, label=6](f){F}
(1, 1) node[circle, black, draw, label=7](g){G}
(2.5, 1) node[circle, black, draw, label=8](h){H}
(4, 1) node[circle, black, draw, label=9](i){I};