大家请看我做出的结果

firm	effch	techch	pech	sech	tfpch
1	1.012	0.992	1.004	1.008	1.004
2	1.006	0.996	1.004	1.002	1.002
3	1.002	0.982	1.001	1.001	0.984
4	1.020	0.993	1.016	1.004	1.013
5	1.011	nan	1.010	1.001	nan
6	1.009	1.001	1.005	1.004	1.010

这个红色nan该怎么解释啊

还有

firm	effch	techch	pech	sech	tfpch
1	1.005	1.036	0.994	1.011	1.042
2	0.999	1.032	1.000	0.999	1.030
3	1.036	1.025	1.015	1.020	1.062
4	1.004	1.034	0.997	1.008	1.038
5	1.046	1.020	1.046	1.001	1.067
6	1.007	1.041	1.000	1.007	1.048
7	1.032	1.038	1.040	0.992	1.071
8	1.161	6.628	1.000	1.161	7.795

这个远远超于1的该怎么解释啊