| 年级 单词级别 | 一年级 | 二年级 | 三年级 | 四年级 |
| 0~1,000 | 72.01% | 63.87% | 66.38% | 64.92% |
| 1,000~2,000 | 13.00% | 18.50% | 17.96% | 16.67% |
| 学术词汇 | 4.68% | 4.36% | 4.19% | 4.65% |
| 其它 | 10.30% | 13.26% | 11.46% | 13.76% |