老师好，在应用stata进行单个率meta分析过程中，发现率为1的数据被自动移除了，是什么原因？要怎么处理？

Study | ES [95% Conf. Interval]

> % Weight

---------------------+---------------------------------

> ------------------

2 | 0.852 0.718 0.986

> 18.78

3 | 0.400 -0.029 0.829

> 2.97

4 | 0.735 0.587 0.884

> 16.63

6 | 0.917 0.760 1.073

> 15.55

7 | 0.714 0.596 0.833

> 21.51

8 | 0.667 0.289 1.044

> 3.77

10 | 0.727 0.464 0.990

> 7.11

11 | 0.867 0.695 1.039

> 13.68

1 | (Excluded)

5 | (Excluded)

9 | (Excluded)

---------------------+---------------------------------

> ------------------

D+L pooled ES | 0.786 0.709 0.862

> 100.00

---------------------+---------------------------------

> ------------------

Heterogeneity chi-squared = 9.99 (d.f. = 7) p = 0.1

> 89

I-squared (variation in ES attributable to heterogene

> ity) = 29.9%

Estimate of between-study variance Tau-squared = 0.0

> 035

Test of ES=0 : z= 20.11 p = 0.000

study cr mrd sum rate ser _LCI _UCI _WT

Dai et al 6 6 6 1 0 1 1 0

Gardner et al 23 22 27 .8518519 .0683673 .7178545 .9858493 18.78337

Jain et al 2 5 .4 .219089 -.0294066 .8294066 2.967256

Pan et al 25 34 .7352941 .0756611 .587001 .8835872 16.63361

Pan et al 20 20 20 1 0 1 1 0

Schultz et al 11 12 .9166667 .0797856 .7602898 1.073044 15.54763

Shah et al 40 35 56 .7142857 .0603682 .5959663 .8326052 21.50821

Singh et al 4 6 .6666667 .1924501 .2894714 1.043862 3.770635

Yang et al 10 8 10 1 0 1 1 0

Yang et al 8 6 11 .7272727 .1342816 .4640856 .9904599 7.105985

Autolus Limited 13 13 15 .8666667 .0877707 .6946391 1.038694 13.6833