|  | Cluster 1a | Cluster 2 | Cluster 3 | Cluster 4 |
---|---|---|---|---|---|
Difference cities | |||||
 Beijing | N | 46 | 89 | 53 | 26 |
 N = 214 | % | 21.50 | 41.59 | 24.77 | 12.15 |
 Guangzhou | N | 10 | 36 | 85 | 49 |
 N = 180 | % | 5.56 | 20.00 | 47.22 | 27.22 |
 Suzhou | N | 10 | 35 | 71 | 66 |
 N = 182 | % | 5.49 | 19.23 | 39.01 | 36.26 |
Different lactation stages | |||||
 0-4d | N | 7 | 39 | 51 | 9 |
 N = 106 | % | 6.60 | 36.79 | 48.11 | 8.49 |
 5-30d | N | 23 | 43 | 91 | 30 |
 N = 187 | % | 12.30 | 22.99 | 48.66 | 16.04 |
 31-240d | N | 36 | 78 | 67 | 102 |
 N = 283 | % | 12.72 | 27.56 | 23.67 | 36.04 |